diff --git a/src/validationthread.cpp b/src/validationthread.cpp
index fd19470..1ec4c9c 100644
--- a/src/validationthread.cpp
+++ b/src/validationthread.cpp
@@ -1,4 +1,5 @@
 #include "wx/wx.h"
+#include "xmlctrl.h"
 #include "validationthread.h"
 #include "wrapxerces.h"
 #include <stdexcept>
@@ -31,17 +32,23 @@ void *ValidationThread::Entry()
 {
 	std::auto_ptr<WrapXerces> validator ( new WrapXerces() );
 	
+	{
+		//wxCriticalSectionLocker locker ( xmlcopyeditorCriticalSection );
 		if ( *myReleasePtr || TestDestroy()  )
 		{
 			Exit();
 			return NULL;
 		}
+	}
 	
 	bool res = validator->validateMemory (
 		myBuffer.c_str(),
 		mySystem.c_str(),
 		myBuffer.size() );
 	
+	
+	{
+		//wxCriticalSectionLocker locker ( xmlcopyeditorCriticalSection );
 		if ( *myReleasePtr  || TestDestroy() )
 		{
 			Exit();
@@ -60,13 +67,16 @@ void *ValidationThread::Entry()
 			*myPositionPtr = std::make_pair ( 0, 0 );
 			*myMessagePtr = "";
 		}
+	}
 	return NULL;
 }
 
 void ValidationThread::OnExit()
 {
-	if ( *myReleasePtr )
-		return;
-
-	*myFinishedPtr = true;
+	{
+		//wxCriticalSectionLocker locker ( xmlcopyeditorCriticalSection );
+		if ( *myReleasePtr )
+			return;
+		*myFinishedPtr = true;
+	}
 }
diff --git a/src/xmlctrl.cpp b/src/xmlctrl.cpp
index e5200f2..9e98c54 100755
--- a/src/xmlctrl.cpp
+++ b/src/xmlctrl.cpp
@@ -68,10 +68,12 @@ XmlCtrl::XmlCtrl (
 	validationThread = NULL;
 	validationStarted = false;
 	validationFinished = false;
-	validationRelease = false;
 	grammarFound = false;
 	validationRequired = (buffer) ? true : false; // NULL for plain XML template
 
+	validationReleasePtr = new bool;
+	*validationReleasePtr = false;
+	
 	currentMaxLine = 1;
 
 	applyProperties ( propertiesParameter );
@@ -122,6 +124,28 @@ XmlCtrl::XmlCtrl (
 	IndicatorSetForeground ( 0, *wxRED );
 }
 
+
+XmlCtrl::~XmlCtrl()
+{
+	attributeMap.clear();
+	elementMap.clear();
+	entitySet.clear();
+
+	if ( validationStarted && !validationFinished )
+	{
+		*validationReleasePtr = true;
+
+		// don't delete validationReleasePtr because the thread will check the value before exiting
+		// this means that 1 variable of type bool will be leaked in this case
+		// the alternative is waiting for the validation thread to finish, which can take anything up to several minutes
+		return;
+	}
+	
+	delete validationReleasePtr;
+		
+}
+
+
 // taken from wxStyledNotebook (c) Eran Ifrah <eranif@bezeqint.net>
 static wxColor LightColour ( const wxColour& color, int percent )
 {
@@ -2028,18 +2052,18 @@ bool XmlCtrl::backgroundValidate (
 	wxCriticalSectionLocker locker ( xmlcopyeditorCriticalSection );
 	if ( validationStarted && !validationFinished )
 	{
-		validationRelease = true;
+		*validationReleasePtr = true;
 		return true; // wait for next idle cycle call from main app frame
 	}
 	validationRequired = false;
 	
-	validationRelease = false;
+	*validationReleasePtr = false;
 	validationThread = new ValidationThread(
 		buffer,
 		system,
 		&validationFinished,
 		&validationSuccess,
-		&validationRelease,
+		validationReleasePtr,
 		&validationPosition,
 		&validationMessage
 	);
diff --git a/src/xmlctrl.h b/src/xmlctrl.h
index 54968a7..cb71a2b 100755
--- a/src/xmlctrl.h
+++ b/src/xmlctrl.h
@@ -107,15 +107,7 @@ class XmlCtrl: public wxStyledTextCtrl
 		    const wxPoint &position = wxDefaultPosition,
 		    const wxSize& size = wxDefaultSize,
 		    long style = 0 );
-		~XmlCtrl()
-		{
-			attributeMap.clear();
-			elementMap.clear();
-			entitySet.clear();
-			
-			// don't delete thread in case it's gone - just set the release flag
-			validationRelease = true;
-		}
+		~XmlCtrl();
 		int getType();
 		int getParentCloseAngleBracket ( int pos, int range = USHRT_MAX * 4 );
 		void applyProperties (
@@ -157,8 +149,8 @@ class XmlCtrl: public wxStyledTextCtrl
 		ValidationThread *validationThread;
 		bool validationStarted,
 			validationFinished,
-			validationSuccess,
-			validationRelease;
+			validationSuccess;
+		bool *validationReleasePtr;
 		std::pair<int, int> validationPosition;
 		std::string validationMessage;