I have XUbuntu Dapper 6.06 installed on my PC. I have dual-booting setup for Windows XP and XUbuntu. The problem is I can't boot into Linux anymore. It's giving me an error right after initrd loads that says:

mount: Mounting /dev/sda4 on /root failed: No such device

It then brings me to a BusyBox cmd line. The Windows XP boots up fine, so I know it's not a loose HDD cable or anything physical. The last thing I was doing was trying to get Compiz/XGL working on XUbunutu. I rebooted and it gave me these errors. I tried manually mounting /dev/sda4 to /mnt and it gives me the error:

mount: Mounting /dev/sda4 on /mnt failed: Invalid argument

I have not modified my /etc/fstab since I installed XUbunutu. I'm puzzled...

Oh yea, I can mount the sda4 partition from my xubuntu live cd just fine. My partitioning scheme is like this:

/dev/sda1 (fat16) dell utility partition
/dev/sda2 (ntfs) winxp
/dev/sda3 (extended)
/dev/sda5 (ntfs) data_backup
/dev/sda6 (linux swap)
/dev/sda4 (ext3) linux root install