Index: src/wp/ap/xp/ap_Dialog_Latex.h
===================================================================
--- src/wp/ap/xp/ap_Dialog_Latex.h	(revision 23366)
+++ src/wp/ap/xp/ap_Dialog_Latex.h	(working copy)
@@ -58,6 +58,7 @@
 private:
 	UT_UTF8String m_sLatex;
 	UT_UTF8String m_sMathML;
+	UT_UTF8String m_sBackupLatex;
 };
 
 #endif /* AP_DIALOG_LATEX_H */
Index: src/wp/ap/xp/ap_Dialog_Latex.cpp
===================================================================
--- src/wp/ap/xp/ap_Dialog_Latex.cpp	(revision 23366)
+++ src/wp/ap/xp/ap_Dialog_Latex.cpp	(working copy)
@@ -102,12 +102,18 @@
 
 void  AP_Dialog_Latex::fillLatex(UT_UTF8String & sLatex)
 {
-        setLatex(sLatex);
+	if (m_sBackupLatex.size())
+		m_sBackupLatex.clear();
+	m_sBackupLatex += sLatex;
+	setLatex(sLatex);
 	setLatexInGUI();
 }
 
 void AP_Dialog_Latex::insertIntoDoc(void)
 {
+	if (m_sBackupLatex.size() == m_sLatex.size())
+		if (m_sBackupLatex == m_sLatex)
+			return;
 	XAP_Frame * pFrame = getActiveFrame();
 	FV_View * pView = static_cast<FV_View *>(pFrame->getCurrentView());
 	pView->cmdInsertLatexMath(m_sLatex,m_sMathML);