Comment 4 for bug 499256

Revision 1869 should help. It's not perfect and it does still leak, but hopefully it can be considered insignificant. However, it *really* should not leak any more if there are no changes (e.g. in window focus/opening or workspace switching or background image changing). There's probably more that I can do, but that's all that I can currently see. Please let me know how it works.