diff --git a/code/ryzom/server/src/ai_service/script_vm.cpp b/code/ryzom/server/src/ai_service/script_vm.cpp
index 243110520..61d54988b 100644
--- a/code/ryzom/server/src/ai_service/script_vm.cpp
+++ b/code/ryzom/server/src/ai_service/script_vm.cpp
@@ -132,11 +132,13 @@ void CScriptVM::interpretCode(
 	size_t index = startIndex;
 	string currentString;
 	
+	nldebug("interpretCode start - thisContext %lx", thisContext);
 	while (index < opcodes.size())
 	{
 	#if !FINAL_VERSION
 		EOpcode	op = (EOpcode)opcodes[index];
 	#endif
+		nldebug("%d", opcodes[index]);
 		
 		switch (opcodes[index])
 		{
@@ -146,9 +148,11 @@ void CScriptVM::interpretCode(
 			nlassert(false);
 			break;
 		case	EOP:
+			nldebug("EOP");
 			return;		//	End Of Program
 
 		case	EQ:		//	==		Need: Value1: Value2 After: Value1==Value2 (Boolean as float)
+			nldebug("EQ");
 			{
 				const	float	res=stack.top(1)==stack.top()?1.f:0.f;
 				stack.pop();
@@ -157,6 +161,7 @@ void CScriptVM::interpretCode(
 			}
 			continue;
 		case	NEQ:	//	!=		Need: Value1: Value2 After: Value1!=Value2 (Boolean as float)
+			nldebug("NEQ");
 			{
 				const	float	res=stack.top(1)!=stack.top()?1.f:0.f;
 				stack.pop();
@@ -165,6 +170,7 @@ void CScriptVM::interpretCode(
 			}
 			continue;
 		case	INF:	//	<		Need: Value1: Value2 After: Value1<Value2 (Boolean as float)
+			nldebug("INF");
 			{
 				const	float	res=stack.top(1)<stack.top()?1.f:0.f;
 				stack.pop();
@@ -173,6 +179,7 @@ void CScriptVM::interpretCode(
 			}
 			continue;
 		case	INFEQ:	//	<=		Need: Value1: Value2 After: Value1<=Value2 (Boolean as float)
+			nldebug("INFEQ");
 			{
 				const	float	res=stack.top(1)<=stack.top()?1.f:0.f;
 				stack.pop();
@@ -181,6 +188,7 @@ void CScriptVM::interpretCode(
 			}
 			continue;
 		case	SUP:	//	>		Need: Value1: Value2 After: Value1>Value2 (Boolean as float)
+			nldebug("SUP");
 			{
 				const	float	res=stack.top(1)>stack.top()?1.f:0.f;
 				stack.pop();
@@ -189,6 +197,7 @@ void CScriptVM::interpretCode(
 			}
 			continue;
 		case	SUPEQ:	//	>=		Need: Value1: Value2 After: Value1>=Value2 (Boolean as float)
+			nldebug("SUPEQ");
 			{
 				const	float	res=stack.top(1)>=stack.top()?1.f:0.f;
 				stack.pop();
@@ -197,6 +206,7 @@ void CScriptVM::interpretCode(
 			}
 			continue;
 		case	ADD:	//	+		Need: Value1: Value2 After: Value1+Value2
+			nldebug("ADD");
 			{
 				CScriptStack::CStackEntry	&entry0=stack.top();
 				CScriptStack::CStackEntry	&entry1=stack.top(1);
@@ -232,6 +242,7 @@ void CScriptVM::interpretCode(
 			}
 			continue;
 		case	SUB:	//	-		Need: Value1: Value2 After: Value1-Value2
+			nldebug("SUB");
 			{
 				const	float	val=stack.top();
 				stack.pop();
@@ -240,6 +251,7 @@ void CScriptVM::interpretCode(
 			}
 			continue;
 		case	MUL:	//	*		Need: Value1: Value2 After: Value1/Value2
+			nldebug("MUL");
 			{
 				float	&res=stack.top(1);
 				res*=(float&)stack.top();
@@ -248,6 +260,7 @@ void CScriptVM::interpretCode(
 			}
 			continue;
 		case	DIV:	//	/		Need: Value1: Value2 After: Value1/Value2	!Exception Gestion.
+			nldebug("DIV");
 			{
 				float	&res=stack.top(1);
 				const	float	&divisor=stack.top();
@@ -260,6 +273,7 @@ void CScriptVM::interpretCode(
 			}
 			continue;
 		case	AND:	//	&&		Need: Value1: Value2 After: Value1&&Value2
+			nldebug("AND");
 			{
 				const	bool	val1=(float&)stack.top(1)!=0.f;
 				const	bool	val2=(float&)stack.top()!=0.f;
@@ -269,6 +283,7 @@ void CScriptVM::interpretCode(
 			}
 			continue;
 		case	OR:		//	||		Need: Value1: Value2 After: Value1||Value2
+			nldebug("OR");
 			{
 				const	bool	val1=(float&)stack.top(1)!=0.f;
 				const	bool	val2=(float&)stack.top()!=0.f;
@@ -278,6 +293,7 @@ void CScriptVM::interpretCode(
 			}
 			continue;
 		case	NOT:	//	!		Need: Value After: !Value
+			nldebug("NOT");
 			{
 				float	&val=stack.top();
 				val=(val==0.f)?1.f:0.f;
@@ -285,18 +301,21 @@ void CScriptVM::interpretCode(
 			}
 			continue;
 		case	PUSH_ON_STACK:	//	Set a Value (float)						Need: - After: Value(float)
+			nldebug("PUSH_ON_STACK");
 			{
 				stack.push(*((float*)&opcodes[index+1]));
 				index+=2;
 			}
 			continue;
 		case	POP:		//	Pop										Need: ValToPop After: -
+			nldebug("POP");
 			{
 				stack.pop();
 				index++;
 			}
 			continue;
 		case	SET_VAR_VAL:		//	Set a Value to a Var.				Need: VarName:	VarValue After:	-
+			nldebug("SET_VAR_VAL");
 			{
 				float f = 0.0f;
 				switch	(stack.top().type())
@@ -321,6 +340,7 @@ void CScriptVM::interpretCode(
 			}
 			continue;
 		case	SET_STR_VAR_VAL:		//	Set a Value to a Var.				Need: VarName:	VarValue After:	-
+			nldebug("SET_STR_VAR_VAL");
 			{
 				switch (stack.top().type())
 				{
@@ -344,6 +364,7 @@ void CScriptVM::interpretCode(
 			}
 			continue;
 		case	SET_CTX_VAR_VAL:		//	Set a Value to a Var.				Need: VarName:	VarValue After:	-
+			nldebug("SET_CTX_VAR_VAL");
 			{
 				switch (stack.top().type())
 				{
@@ -361,6 +382,7 @@ void CScriptVM::interpretCode(
 			}
 			continue;
 		case	PUSH_VAR_VAL:	//	Push the Value of a Var.			Need: - (VarName on next IP) After:	VarValue(float)
+			nldebug("PUSH_VAR_VAL");
 			{
 				const	float	f=thisContext->getLogicVar(*((TStringId*)&opcodes[index+1]));
 				stack.push(f);
@@ -368,6 +390,7 @@ void CScriptVM::interpretCode(
 			}
 			continue;
 		case	PUSH_STR_VAR_VAL:	//	Push the Value of a Var.			Need: - (VarName on next IP) After:	VarValue(float)
+			nldebug("PUSH_STR_VAR_VAL");
 			{
 				std::string str = thisContext->getStrLogicVar(*((TStringId*)&opcodes[index+1]));
 				stack.push(str);
@@ -375,6 +398,7 @@ void CScriptVM::interpretCode(
 			}
 			continue;
 		case	PUSH_CTX_VAR_VAL:	//	Push the Value of a Var.			Need: - (VarName on next IP) After:	VarValue(float)
+			nldebug("PUSH_CTX_VAR_VAL");
 			{
 				IScriptContext* ctx = thisContext->getCtxLogicVar(*((TStringId*)&opcodes[index+1]));
 				stack.push(ctx);
@@ -581,6 +605,7 @@ void CScriptVM::interpretCode(
 			continue;
 		*/
 		case	SET_CONTEXT_VAR_VAL:
+			nldebug("SET_CONTEXT_VAR_VAL");
 			{
 				IScriptContext* otherContext = (IScriptContext*)0;
 				switch (stack.top().type())
@@ -619,6 +644,7 @@ void CScriptVM::interpretCode(
 			}
 			continue;
 		case	SET_CONTEXT_STR_VAR_VAL:
+			nldebug("SET_CONTEXT_STR_VAR_VAL");
 			{
 				IScriptContext* otherContext = (IScriptContext*)0;
 				switch (stack.top().type())
@@ -657,6 +683,7 @@ void CScriptVM::interpretCode(
 			}
 			continue;
 		case	SET_CONTEXT_CTX_VAR_VAL:
+			nldebug("SET_CONTEXT_CTX_VAR_VAL");
 			{
 				IScriptContext* otherContext = (IScriptContext*)0;
 				switch (stack.top().type())
@@ -689,6 +716,7 @@ void CScriptVM::interpretCode(
 			}
 			continue;
 		case	PUSH_CONTEXT_VAR_VAL:
+			nldebug("PUSH_CONTEXT_VAR_VAL");
 			{
 				IScriptContext* otherContext = (IScriptContext*)0;
 				switch (stack.top().type())
@@ -714,6 +742,7 @@ void CScriptVM::interpretCode(
 			}
 			continue;
 		case	PUSH_CONTEXT_STR_VAR_VAL:
+			nldebug("PUSH_CONTEXT_STR_VAR_VAL");
 			{
 				IScriptContext* otherContext = (IScriptContext*)0;
 				switch (stack.top().type())
@@ -737,6 +766,7 @@ void CScriptVM::interpretCode(
 			}
 			continue;
 		case	PUSH_CONTEXT_CTX_VAR_VAL:
+			nldebug("PUSH_CONTEXT_CTX_VAR_VAL");
 			{
 				IScriptContext* otherContext = (IScriptContext*)0;
 				switch (stack.top().type())
@@ -760,11 +790,13 @@ void CScriptVM::interpretCode(
 			}
 			continue;
 		case	JUMP:		//	Jump + nb size_t to jump (relative).	Need: NewJumpOffset After: -
+			nldebug("JUMP");
 			{
 				index+=opcodes[index+1]+1;	//	AGI .. Not Opt
 			}
 			continue;
 		case	JE:			//	Jump if last stack value is FALSE(==0).	Need: BoolValue(float) (NewJumpOffset on  Next Ip) After: -
+			nldebug("JE");
 			{
 				if ((float&)stack.top()==0.f)
 					index+=opcodes[index+1]+1;	//	AGI .. Not Opt
@@ -774,6 +806,7 @@ void CScriptVM::interpretCode(
 			}
 			continue;
 		case	JNE:		//	Jump if last stack value is TRUE(!=0).	Need: BoolValue(float) (NewJumpOffset on  Next Ip) After: -
+			nldebug("JNE");
 			{
 				if ((float&)stack.top()!=0.f)
 					index+=opcodes[index+1]+1;	//	AGI .. Not Opt
@@ -783,12 +816,14 @@ void CScriptVM::interpretCode(
 			}
 			continue;
 		case	PUSH_PRINT_STRING:
+			nldebug("PUSH_PRINT_STRING");
 			{
 				currentString+=CStringMapper::unmap(*((TStringId*)&opcodes[index+1]));	//	strPt.substr(1,strPt.size()-2);
 				index+=2;
 			}
 			continue;
 		case	PUSH_PRINT_VAR:
+			nldebug("PUSH_PRINT_VAR");
 			{
 				float const val = thisContext->getLogicVar(*((TStringId*)&opcodes[index+1]));
 				currentString += NLMISC::toString("%g", val);
@@ -796,6 +831,7 @@ void CScriptVM::interpretCode(
 			}
 			continue;
 		case	PUSH_PRINT_STR_VAR:
+			nldebug("PUSH_PRINT_STR_VAR");
 			{
 				string const str = thisContext->getStrLogicVar(*((TStringId*)&opcodes[index+1]));
 				currentString += str;
@@ -803,6 +839,7 @@ void CScriptVM::interpretCode(
 			}
 			continue;
 		case	PRINT_STRING:
+			nldebug("PRINT_STRING");
 			{
 				if (AIScriptDisplayPrint)
 				{
@@ -813,6 +850,7 @@ void CScriptVM::interpretCode(
 			}
 			continue;
 		case	LOG_STRING:
+			nldebug("LOG_STRING");
 			{
 				if (AIScriptDisplayLog)
 				{
@@ -823,6 +861,7 @@ void CScriptVM::interpretCode(
 			}
 			continue;
 		case	FUNCTION:
+			nldebug("FUNCTION");
 			{
 				// on_event
 				TStringId const eventName = *((TStringId*)&opcodes[index+1]);
@@ -835,6 +874,7 @@ void CScriptVM::interpretCode(
 			}
 			continue;
 		case	CALL:
+			nldebug("CALL");
 			{
 				// set_event
 				const	TStringId	eventName=*((TStringId*)&opcodes[index+1]);
@@ -850,11 +890,13 @@ void CScriptVM::interpretCode(
 		case	PUSH_THIS:
 			{
 				IScriptContext* const	sc=thisContext;
+				nldebug("PUSH_THIS (%lx)", sc);
 				stack.push(sc);
 				index++;
 			}
 			continue;
 		case	PUSH_GROUP:
+			nldebug("PUSH_GROUP");
 			{
 				const	TStringId	strId=*((TStringId*)&opcodes[index+1]);
 				
@@ -881,11 +923,13 @@ void CScriptVM::interpretCode(
 		case	PUSH_STRING:
 			{
 				const	string &str = CStringMapper::unmap(*((TStringId*)&opcodes[index+1]));
+				nldebug("PUSH_STRING (%s)", str.c_str());
 				stack.push(str);
 				index+=2;
 			}
 			continue;
 		case	ASSIGN_FUNC_FROM:
+			nldebug("ASSIGN_FUNC_FROM");
 			{
 				const	TStringId	srcFunc=CStringMapper::map(stack.top());
 				stack.pop();
@@ -910,6 +954,7 @@ void CScriptVM::interpretCode(
 			}
 			continue;
 		case	NATIVE_CALL:
+			nldebug("NATIVE_CALL");
 			{
 				IScriptContext* const sc = stack.top();
 				stack.pop();
@@ -919,6 +964,7 @@ void CScriptVM::interpretCode(
 				string const& outParamsSig = CStringMapper::unmap(*((TStringId*)&opcodes[++index]));
 				if (sc)
 				{
+					nldebug ("launch callNativeCallBack: %lx funcName:%s mode:%d inParamsSig:'%s' outParamsSig:'%s'", sc, funcName.c_str(), mode, inParamsSig.c_str(), outParamsSig.c_str());
 					sc->callNativeCallBack(thisContext, funcName, mode, inParamsSig, outParamsSig, &stack);
 				}
 				else
@@ -949,6 +995,7 @@ void CScriptVM::interpretCode(
 			}
 			continue;
 		case	RAND:
+			nldebug("RAND");
 			{
 				const	size_t	randIndex=rand32((uint32)opcodes[index+1]); // rand(RANDCOUNT)
 				index+=3;	//	pass RAND + RANDCOUNT + 1
@@ -960,12 +1007,14 @@ void CScriptVM::interpretCode(
 			}
 			continue;
 		case	RET:
+			nldebug("RET");
 			{
 				index=(int&)stack.top();
 				stack.pop();
 			}
 			continue;
 		case	ONCHILDREN:
+			nldebug("ONCHILDREN");
 			{
 				if (thisContext)
 				{
@@ -975,6 +1024,7 @@ void CScriptVM::interpretCode(
 			}
 			continue;
 		case	SWITCH:
+			nldebug("SWITCH");
 			{
 			//	!!!!!
 				size_t	compValue=0;
@@ -1027,6 +1077,7 @@ void CScriptVM::interpretCode(
 			}
 			continue;
 		case	INCR:		//	Increment top of stack.
+			nldebug("INCR");
 			{
 				float &f = stack.top();
 				++f;
@@ -1034,6 +1085,7 @@ void CScriptVM::interpretCode(
 			}
 			continue;
 		case	DECR:		//	Decrement top of stack.
+			nldebug("DECR");
 			{
 				float &f = stack.top();
 				--f;
@@ -1041,12 +1093,14 @@ void CScriptVM::interpretCode(
 			}
 			continue;
 		case	CONCAT:		//	Concatenates 2 strings
+			nldebug("CONCAT");
 			{
 				(string&)stack.top(1) += (string&)stack.top();
 				stack.pop();
 			}
 			continue;
 		case	FTOS:		//	Convert a float to a string
+			nldebug("FTOS");
 			{
 				stack.top()=NLMISC::toString("%g", (float&)stack.top());
 			}
@@ -1054,6 +1108,7 @@ void CScriptVM::interpretCode(
 		}
 		nlassert(false);	//	must use continue !!	Not implemented.
 	}
+	nldebug("interpretCode end");
 }
 
 }
diff --git a/code/ryzom/server/src/ai_service/script_vm.h b/code/ryzom/server/src/ai_service/script_vm.h
index 0b931c63d..15a9f4121 100644
--- a/code/ryzom/server/src/ai_service/script_vm.h
+++ b/code/ryzom/server/src/ai_service/script_vm.h
@@ -21,6 +21,7 @@
 //#include "ai_grp.h"
 
 #include <limits>
+#include <nel/misc/debug.h>
 
 namespace AIVM
 {
@@ -310,6 +311,7 @@ inline
 CByteCode::CByteCode(std::string const& sourceName)
 : _sourceName(sourceName)
 {
+	nldebug("[%lx]", this);
 }
 
 inline
@@ -334,17 +336,20 @@ inline
 CScriptStack::CStackEntry::CStackEntry()
 : _type(ENone)
 {
+	nldebug("[%lx]", this);
 }
 
 inline
 CScriptStack::CStackEntry::~CStackEntry()
 {
+	nldebug("[%lx]", this);
 	clean();
 }
 
 inline
 void CScriptStack::CStackEntry::clean()
 {
+	nldebug("[%lx]", this);
 	if (_type==EString)
 		delete &getString();
 }
@@ -352,6 +357,7 @@ void CScriptStack::CStackEntry::clean()
 inline
 CScriptStack::CStackEntry& CScriptStack::CStackEntry::operator=(float const& f)
 {
+	nldebug("[%lx] float:'%f'", this, f);
 	clean();
 	_valf = f;
 	_type = EFloat;
@@ -360,6 +366,7 @@ CScriptStack::CStackEntry& CScriptStack::CStackEntry::operator=(float const& f)
 inline
 CScriptStack::CStackEntry& CScriptStack::CStackEntry::operator=(int const& i)
 {
+	nldebug("[%lx] int:'%d'", this, i);
 	clean();
 	_vali = i;
 	_type = EOther;
@@ -368,6 +375,7 @@ CScriptStack::CStackEntry& CScriptStack::CStackEntry::operator=(int const& i)
 inline
 CScriptStack::CStackEntry& CScriptStack::CStackEntry::operator=(std::string const& str)
 {
+	nldebug("[%lx] string:'%s'", this, str.c_str());
 	clean();
 	std::string* const strPt = new std::string(str);
 	_valsp = strPt;
@@ -377,6 +385,7 @@ CScriptStack::CStackEntry& CScriptStack::CStackEntry::operator=(std::string cons
 inline
 CScriptStack::CStackEntry& CScriptStack::CStackEntry::operator=(IScriptContext* sc)
 {
+	nldebug("[%lx] IScriptContext:[%lx]", this, sc);
 	clean();
 	_valp = (uintptr_t) sc;
 	_type = EContext;
@@ -553,17 +562,20 @@ void CScriptStack::push(int val)
 inline
 CScriptStack::CStackEntry& CScriptStack::top()	//	is this an optimisation of the method below ?
 {
+	nldebug("[%lx]", this);
 	return _Stack.back();
 }
 inline
 CScriptStack::CStackEntry& CScriptStack::top(int index)
 {
+	nldebug("[%lx] index:%d", this, index);
 	return *(_Stack.rbegin()+index);
 }
 
 inline
 void CScriptStack::pop()
 {
+	nldebug("[%lx]", this);
 	_Stack.pop_back();
 }
 
diff --git a/code/ryzom/server/src/ai_service/state_instance.h b/code/ryzom/server/src/ai_service/state_instance.h
index 916b6bc47..d7de97f18 100644
--- a/code/ryzom/server/src/ai_service/state_instance.h
+++ b/code/ryzom/server/src/ai_service/state_instance.h
@@ -505,7 +505,10 @@ void CStateInstance::processStateEvent(CAIEvent const& stateEvent, CAIState cons
 
 		getDebugHistory()->addHistory("STATE: '%s' EVENT: '%s' REACTION: '%s'",	state->getAliasNode()->fullName().c_str(),
 			stateEvent.getName().c_str(),	reaction.getAliasNode()->fullName().c_str());
-
+		nldebug("STATE: '%s' EVENT: '%s' REACTION: '%s'",
+			state->getAliasNode()->fullName().c_str(),
+			stateEvent.getName().c_str(),
+			reaction.getAliasNode()->fullName().c_str());
 		foundReaction=true;
 
 		if (!reaction.getAction())