diff -up wmakerconf-2.12/src/themebrowser.c.segfault wmakerconf-2.12/src/themebrowser.c
--- wmakerconf-2.12/src/themebrowser.c.segfault	2011-07-23 21:04:58.532814413 +0200
+++ wmakerconf-2.12/src/themebrowser.c	2011-07-23 22:00:22.651320896 +0200
@@ -2881,7 +2881,10 @@ get_theme_attributes (void)
 void
 cleanup_themes (void)
 {
-   WMReleasePropList (theme_keys);
+   if (theme_keys != NULL)
+   {
+      WMReleasePropList (theme_keys);
+   }
 }
 
 static void