Comment 5 for bug 651803

I think it's more a problem of appmenu.

I did something yesterday (I forgot, probably open some app and click the appmenu at the same time) and the same scenario happened. So I tried to reproduce it and succeeded!

Just open some app and before it opens click on the appmenu (it's now showing, say, nautilus' menus), upon the startup of new app, appmenu changes to menus for the new one and the whole UI freezes. I'll go ahead and report this to them.