Index: _whatsnew.html
===================================================================
--- _whatsnew.html	(revision 1688)
+++ _whatsnew.html	(working copy)
@@ -58,6 +58,9 @@
 			mode.</li>
 		<li>[<a target="_blank" href="http://dev.fckeditor.net/ticket/1934">#1934</a>] Fixed
 			JavaScript errors when calling Selection.EnsureSelection() in dialogs.</li>
+		<li>[<a target="_blank" href="http://dev.fckeditor.net/ticket/1055">#1055</a>] Added logic
+			to override JavaScript errors occuring inside the editing frame due to user added
+			JavaScript code.</li>
 	</ul>
 	<h3>
 		Version 2.6 Beta 1</h3>
Index: editor/_source/classes/fckeditingarea.js
===================================================================
--- editor/_source/classes/fckeditingarea.js	(revision 1688)
+++ editor/_source/classes/fckeditingarea.js	(working copy)
@@ -92,12 +92,16 @@
 		// Create the editing area IFRAME.
 		var oIFrame = this.IFrame = oTargetDocument.createElement( 'iframe' ) ;
 
+		// IE: Avoid JavaScript errors thrown by the editing are source (like tags events).
+		// See #1055.
+		var sOverrideError = '<script>window.onerror=function(){return true;};//FCK_IGNORE</script>' ;
+
 		oIFrame.frameBorder = 0 ;
 		oIFrame.width = oIFrame.height = '100%' ;
 
 		if ( FCK_IS_CUSTOM_DOMAIN && FCKBrowserInfo.IsIE )
 		{
-			window._FCKHtmlToLoad = html ;
+			window._FCKHtmlToLoad = sOverrideError + html ;
 			oIFrame.src = 'javascript:void( (function(){' +
 				'document.open() ;' +
 				'document.domain="' + document.domain + '" ;' +
@@ -129,6 +133,7 @@
 			var oDoc = this.Window.document ;
 
 			oDoc.open() ;
+			oDoc.write( sOverrideError ) ;
 			oDoc.write( html ) ;
 			oDoc.close() ;
 		}
Index: editor/_source/internals/fck.js
===================================================================
--- editor/_source/internals/fck.js	(revision 1688)
+++ editor/_source/internals/fck.js	(working copy)
@@ -248,6 +248,10 @@
 			FCKConfig.IgnoreEmptyParagraphValue,
 			format ) ;
 
+		// Remove <SCRIPT> tags with FCK_IGNORE (For #1055 in full page mode).
+		if ( isFullPage )
+			data = data.replace( /\s*<script[^<>]*>[^<>]*\/\/FCK_IGNORE[^<>]*<\/script>/ig, '' ) ;
+
 		// Restore protected attributes.
 		data = FCK.ProtectEventsRestore( data ) ;