I have a similar problem with 169.04... a slightly different backtrace
0: /usr/bin/X(xf86SigHandler+0x6d) [0x48670d]
1: /lib/libc.so.6 [0x3d36c317d0]
2: /usr/lib/xorg/modules/drivers//nvidia_drv.so [0x2ab220a3dba1]
Fatal server error:
Caught signal 11. Server aborting
This happens *very* often when mplayer/totem exits at eof or by me closing it. These are both currently set to use the xv driver. It happens seemingly at random with just a single file, but with something like 6 or more opened and played simultaneously, its guaranteed to happen when a few or more are closed (pretty certainly by the time I get down to one). I should mention things play fine and there seems to be no problem... until something is closed at which point the system may ( or will probably if >=6 players are opened) freeze. I'm using compiz on ubuntu 7.10 amd64.
ps. I used to get this same problem on the previous 100.x drivers, I was just never able to get a backtrace to figure out what happened to the system until recently (the box used to hard lock until I found that pausing before quiting for some reason seems to lessen the likelyhood of a full on hardlock),