Re: Xorg server crash in nvidia 295.20.
Here to add another data point.
Since updating to the 295.x series I've been getting seemingly random X crashes while browsing, swichting desktops, or just idling (no browsers open). Every one is accompanied by a "NVRM: Xid (0000:01:00): 6, PE0001" error.
-Chrome 21.0.1180.0 dev and Firefox (Iceweasel) 10.0.5
-KDE 4.8.4 (and previously 4.7.x)
-Geforce 8800GT, Debian Wheezy x86 (3.2.0-1-686-pae kernel)
I've had this issue before updating to X server 1.12 as well, and had to revert to the 290.10 driver for a few months (which never crashed), but it seems that's no longer compatible with the new server. I'll probably end up on nouveau if this persists, but I'd rather not have to do that.