Sometimes (rather rarely) when I boot up my laptop, my Gnome3 desktop stops loading. I can move the mouse, but there's nothing else on the screen (except my wallpaper). And it seems that no matter how long I wait, the gnome menubar (the thingie with the Activities and shutdown buttons at the top of the screen) just refuses to load.
Also my processor-usage starts to converge to 100% on all four cores, when this happens.
This problem can be easily solved by restarting gdm3, but it's still annoying and I have no clue why this might happen.
My system uses the standard gnome metapackage from the wheezy repo. (It might or might not be relevant.)
I have no clue what causes this so any ideas are welcome.