Upgrade FC2 to FC3 - get kernel panic

[Cameron Beattie]

I have upgraded from FC2 to FC3 and I am now getting a kernel panic when I 
choose the new kernel (2.6.12-1.1372_FC3smp). The old kernel 
(2.6.10-1.771_FC2smp) still works fine. I get the following messages:
mkrootdev: label / not found
Mounting root filesystem
mount: error 2 mounting ext3
mount: error 2 mounting none
Switching to new root
switchroot: mount failed: 22
umount /initrd/dev failed: 2
Kernel panic - not syncing: Attempted to kill init!

So it seems to be having a mount problem but why would the kernel make a 
difference to that?

I'm a beginner so any help would be appreciated.

Regards

Cameron