Index: /CKEditor/trunk/_source/skins/office2003/dialog.css
===================================================================
--- /CKEditor/trunk/_source/skins/office2003/dialog.css	(revision 7523)
+++ /CKEditor/trunk/_source/skins/office2003/dialog.css	(revision 7524)
@@ -43,5 +43,5 @@
 	_background-image: url(images/sprites_ie6.png);
 	/* Dialog corner parts require a negative z-index to avoid covering dialog body. (#4954) */
-	_z-index: -1;
+	z-index: -1;
 }
 
Index: /CKEditor/trunk/_source/skins/v2/dialog.css
===================================================================
--- /CKEditor/trunk/_source/skins/v2/dialog.css	(revision 7523)
+++ /CKEditor/trunk/_source/skins/v2/dialog.css	(revision 7524)
@@ -44,5 +44,5 @@
 	_background-image: url(images/sprites_ie6.png);
 	/* Dialog corner parts require a negative z-index to avoid covering dialog body. (#4954) */
-	_z-index: -1;
+	z-index: -1;
 }