a few random shots in the dark....
in slackware, the startup script (rc.
deletes "/etc/mtab" since any info there is bound to be out of date. I'm not sure if the other distros do it, or what the Sys V startup script is; check your inittab. hence, no mount info is carried across reboots. (well, almost, but that is an entirely different story.)
the up to date mount table is "/proc/mounts", but i don't know how that will help you. Anyway, since it is kernel space, it will be more up to date than "/etc/mtab".
the man page for mount states that a corrupt file system might crash the system....
how are your cpu temps? I only ask this because you said that is begining to happen more sporradically, not just when doing disk io. I know nothing of laptop internals, but you might want to oil the fans and check the heat sinks just in case....
enough of my ignorant ramblings.
-t.
