Occasionally when i have a lot of applications running ubuntu logs out by itself and prompts me for username and password, which is rather frustrating. This happens to me rarely, so it's not a real problem, yet it's something that i can't bare. I suspect that this is happening (or has something to do) with the fact that i have nVidia drivers enabled and extra visual effects, because this started to happen after i configured my ubuntu that way.
anyone had a similar problem? any solution? (except disabling drivers and effects)