With more recent driver versions I started noticing a crash when using desktop effects on KDE 4 for a prolonged time on 7600GT.
Xorg crashes with this message:
0: /usr/bin/Xorg(xf86SigHandler+0x79) [0x80b3619]
2: /usr/lib/xorg/modules//drivers/nvidia_drv.so(_nv001644X+0x2b) [0xb65e429b]
Fatal server error:
Caught signal 11. Server aborting
There are no Xid messages in dmesg however.
I've attached the older xorg log of crashed session separately.