Hello! Recently Gnome has started crashing, a lot. I thought maybe it was Firefox causing it, but it quite often crashes when I'm running Chromium as well. I'm not really sure where to start with this one. Which log files should I check?

I'm running Ubuntu 9.10, with the nVidia hardware drivers enabled, but otherwise the installation is pretty normal. Basically, I realise it's impossible to solve without more symptoms, but I just want to know which files to look at to diagnose what's causing the problem. It's definitely a Gnome crash, not a full reboot, so I'm presuming it's not a memory / hard drive problem.