GTK+ works better due to avoidance of default list view popups;

--- a/NEWS	Thu Aug 29 08:05:29 2013 +0200
+++ b/NEWS	Thu Aug 29 09:16:03 2013 +0200
@@ -95,6 +95,9 @@
 are only completed in backslash forms, e.g. \forall or \<forall> that
 both produce the Isabelle symbol \<forall> in its Unicode rendering.
 
+* Improved support for Linux look-and-feel "GTK+", see also "Utilities
+/ Global Options / Appearance".
+
 
 *** Pure ***