I've produced the same response having done a moderately large 'empty trash' (about 2 GB) last night (17/4 Oz EST). Immediately after shutting down, the system froze. I probably should not have hit the 'reset' button after 20 mins of waiting, as when I logged back in the following error consistently appears:
EXT3-fs: error loading journal
mount: error 22 mounting ext3
mount: error 2 mounting none
switchroot: mount failed: 22
umount /initrd/dev failed: 2
Kernel panic - not syncing: Attempted to kill init!
Some things to try are:
1. Loading a self booting mini-Linux app (eg SimplyMepis 3.3) and mounting to the area where the inaccessible files are, or
2. If that doesn't work, try reinstalling Fedora Core 3 from the installation media, but don't elect to overwrite the whole hard drive - I once accidentally lost GRUB, and when doing a reinstall managed not to overwrite everything that existed previously. There is an option that allows you to repair at the first installation screen, but the instructions telling me what to do are on the incapacitated drive.
Any expert advice would be appreciated.