With all the 28x versions of the Nvidia drivers, I get random crashes when I switch (with the Gnome desktop switcher/pager) from a desktop where an OpenGL application is running (Second Life viewer) to another desktop.
When it happens (about one time out of 30 desktop switching), The OpenGL application crashes with the following stack trace log:
0xb55dabb0 /usr/lib/libnvidia-glcore.so.285.05.09 [0xb55dabb0]
and the following line in /var/log/messages:
NVRM: Xid (0000:01:00): 31, Ch 00000004, engmask 00000101, intr 10000000
It seems to happens more often while VLC is also running or when the four cores of the CPU are loaded at 100% (the Second Life viewer only loads one at 100%).
I'm running a Mandriva 2010.0 distro with a vanilla Linux kernel (all kernels from v2.6.x to v3.0.x gave the same results).