Crashes instantly after startup :/. Safe-Mode doesn’t help.

I suspect it could have something to do with MESA; my gfx card is a bit oldish and had some trouble with newer applications. But SuperTuxKart and most games still do run, so this assumption is a bit shallow to go out and start to kick around my gfx-drivers.

Do you guys have any idea how to fix it? Using Chromium feels bad ;/. Setting up SeaMonkey right now, it works - at least for now.