Andrew,
Please find attached snippet from kernel log file. Basically, assert
was raised when machine was shutting down as a part of the reboot.
If it matters: I have nVidia kernel module loaded.
Most likely I wouldn't be able to reproduce it because it happened only once out of about 10 reboots.
Kernel version is 2.6.0-test6-mm4 and all packages are updated on daily
basis from Debian/unstable. Kernel config file is also attached
to this letter.
Please feel free to contact me with any questions you might have.