1. # cat /etc/fstab and verify that the / partition is ext3 and not ext2. Also note the mount point for step 4.
2. Reboot the system with the AMP CD in the cd-rom.
3. type linux rescue when prompted.
-this will boot you into single user mode with un-mounted file system.
4. run # fsck.ext3 p [mount point of / partition] (i.e. # Fsck.ext3 p /dev/ VolGroup00/LogVol00)
This will try to repair the file system. If this does not work I would recommend reinstalling AMP and restoring from a recent backup.