ubuntu filesystem check fails on boot

Hello,

I've just installed ubuntu dapper drake, and I have a persistent problem where it fails the filesystem check during bootup, and I get dropped into a root shell. Ignoring the problem lets me boot up, and if I check the filesystem from the live CD (with fsckdev-hda -f) it comes up clean. For some reason it seems to be checking the root filesystem (-dev-hda5) even though that's already been checked earlier on, and should be mounted at this stage. The other filesystems check clean. I looked at the script (-etc-rcS.d-S30checkfs.sh), and the fsck command includes the '-R' flag which should tell it not to check the root filesystem, so I don't understand why this is happening. As far as I can guess, the problem is that: a) for some reason fsck is not picking up the fact that dev-hda5 is mounted as root. b) because of this, it's checking the filesystem while still mounted, and finding an error because of that.

I've tried doing the following: - booting from a live CD and checking the filesystem from that, including a read-write bad blocks test. It always comes up clean or with a minor error, but the same error comes up again when I reboot from the hard disk. - rebuilding my parbreastion table using fdisk (writing down the cylinder numbers, deleting it and recreating it) - looking at fstab. It's pasted below.

#etc-fstab: static file system information. # proc proc proc defaults 0 0dev-hda5 ext3 defaults,errors=remount-ro 0 1 dev-hda3 local ext3 defaults 0 2dev-hda1 media-hda1 ext3 defaults 0 2dev-hda4 media-hda4 ext3 defaults 0 2dev-hda7 var ext3 defaults 0 2dev-hda6 none swap sw 0 0 dev-hdc media-cdrom0 udf,iso9660 user,noauto 0 0 local-home home auto defaults,bind 0 0local-usr-localusr-local auto defaults,bind 0 0

For the moment I'm carrying on using the system as it is, but I'm not happy to do this in the long term if there's a persistent error - any help with this would be appreaciated.