type this to check your root partition:
mount / -o remount,ro
e2fsck -f -v /dev/hda3
If you want to test for bad blocks/sectors:
e2fsck -f -c /dev/hda3
Then change the partition type to ext3 right away:
tune2fs -j /dev/hda3
Update /etc/fstab, set the file system type to ext3.
perhaps you need to reboot, but maybe this command works:
mount / -o remount,rw -t ext3
it remounts your drive in read-write mode again, and sets the file system type to ext3.
If that worked, tell init it should enter the runlevel for graphical login:
you can only perform these actions while you're in single-user mode. (which is the case right now) If you're not in single user mode, type "telinit 1" to enter this mode. It closes all programs and network connections.