It sounds like you were in a write operation when you did a hot shutdown...
This process below MAY or MAY NOT help.
Boot into terminal... Use kubuntu live cd
run
$ sudo e2fsck -pcf /dev/sda1
$ sudo badblocks -sv /dev/sda1
Reboot.
If you can now boot into system and it is operational as far as you can tell...
CREATE A RECOVERY DISK and BACK UP operation system!!
You May be correct in suspecting a HD issue... bad blocks and all... I always recommend to anyone that you should only have hda1 be large enough for the root file system and swap....
You should put all your data on an entirely different disk... That way you can easily back up your working root system... and you can always repair what necessary files that may fail on hdb1... With Drives ranging into the TB sizes they have not become anymore or less reliable but the ratio of failed sectors/cylinders/disks VS size creates An exponential increase in the amount of data corruption in MB.
I remember saving my $ up to get that Enormous 50MB Western Digital...
I thought that drive would last forever... How could you ever use that much space...