My example is different all right but I'll post a pic FWIW
It seems to be related to overload - when I try to open the Sessionsaver sub-menu I get a freeze. There's a lot in that sub-menu (lots of sessions and a long closed-tabs-list).
It's hard to tell if the titlebar is whited-out as well cause it's totally transparent - but I think not. Likewise you can see the menu, but nothing responds - I was so involved in making sure I got a screenshot that I forgot to test for taskmanager
(I can only reproduce this once after rebooting.)WSOD