Originally Posted by Iberwil
There are plenty of live cd system recovery distributions that have some hard drive diagnostic tools. Perhaps you could try running one of them if you've some experience?
OP, you can use the Slackware installation disk for that. boot from it and issue
fsck -N -V your_partition
The -N flag prevents any changes being written to disk. If you feel lucky you can then execute fsck without the -N flag. You might end up with cryptic filenames in lost+found. In that case, if you can't restore them to their original path and filename, you might be hosed.
edit: roar of time would be the appropriate attack - going back to a suitable save point