I'm running Ubuntu 10.10 on my laptop (an Asus G73j), dual-booting Windows 7 if that matters. After using the computer for couple of hours or so, I get a popup complaining that a file was unmounted, then my GNOME desktop panels disappear. I can't save any unsaved work (the file browser shows "Filesystem" as totally empty), and other programs break in odd ways (like Chrome can't browse to any new pages, but keeps current ones going... at least I still have Pandora to listen to when this happens!).

I've tried looking in the system logs to no avail; I'm assuming that it can't write any errors to the logs because, of course, the logs are on the primary hard drives.

This started happening maybe a few days ago. Yesterday I upgraded from 10.4, but I believe it was happening before then. Any advice for figuring this out?

EDIT: It just happened again, and I heard a small little clicky sound from the hard drive about five seconds before things went south. I'm thinking I should start backing up ASAP.

In response to a comment, here's the dmesg output: http://askubuntu.pastebin.com/uYGshBay

Also, the SMART status says the disk has a few bad sectors, and the detailed data says there are 14. It says it passed the self-assessment though.

Lastly, this doesn't seem to be happening when I'm on Windows. I recently re-enabled ureadahead (which I disabled ages ago because it was causing Ubuntu to hang at the startup logo), could that be the source of the problem? I've disabled it again to see.