I previously had my system running with an ATI grapgic card, which caused a very instable system. Therefore I bought a simple Nvidia card which is doing fine, but since then, the Gnome Shell crashes when opening the Gnome Shell Menu 1 and start typing! And it is even funnier that it does NOT crash when typing e.g. "jd.." for jDownloader!
I posted a picture to be sure you know what I mean.