Comment 4 for bug 566324

I think you may mean 'freeze' rather than 'crash'? Most of the issues we've seen reported on i845 have been freezes (black screen, mouse still works, ssh/ping still works, system otherwise unrecoverable)

If it is actually a crash, please run gdb and collect a full backtrace. (See http://wiki.ubuntu.com/X/Backtracing for details)