Index: /CKEditor/trunk/CHANGES.html
===================================================================
--- /CKEditor/trunk/CHANGES.html	(revision 6977)
+++ /CKEditor/trunk/CHANGES.html	(revision 6978)
@@ -83,4 +83,5 @@
 		<li><a href="http://dev.ckeditor.com/ticket/7269">#7269</a> : [WebKit] Paste from Word was including the full "file://" URL for anchor links.</li>
 		<li><a href="http://dev.ckeditor.com/ticket/7584">#7584</a> : Start number of list style dialog now works with numbered list items.</li>
+		<li><a href="http://dev.ckeditor.com/ticket/6975">#6975</a> : Definition list crashes IE6/7 on html output.</li>
 		<li>Updated the following language files:<ul>
 			<li><a href="http://dev.ckeditor.com/ticket/7834">#7834</a> : Dutch;</li>
Index: /CKEditor/trunk/_source/core/htmlparser/fragment.js
===================================================================
--- /CKEditor/trunk/_source/core/htmlparser/fragment.js	(revision 6977)
+++ /CKEditor/trunk/_source/core/htmlparser/fragment.js	(revision 6978)
@@ -41,4 +41,7 @@
 	// parser fixing.
 	var nonBreakingBlocks = CKEDITOR.tools.extend( { table:1,ul:1,ol:1,dl:1 }, CKEDITOR.dtd.table, CKEDITOR.dtd.ul, CKEDITOR.dtd.ol, CKEDITOR.dtd.dl );
+
+	// IE < 8 don't output the close tag on definition list items. (#6975)
+	var optionalCloseTags = CKEDITOR.env.ie && CKEDITOR.env.version < 8 ? { dd : 1, dt :1 } : {};
 
 	var listBlocks = { ol:1, ul:1 };
@@ -194,5 +197,6 @@
 				element.isEmpty = true;
 
-			element.isOptionalClose = optionalClose;
+			// Check for optional closed elements, including browser quirks and manually opened blocks.
+			element.isOptionalClose = tagName in optionalCloseTags || optionalClose;
 
 			// This is a tag to be removed if empty, so do not add it immediately.