changed cases, now freebsd won't boot!

[Brian John]

Hello,
I just switched my computer to a new case yesterday and now it won't 
boot.  However, Windows boots fine (I dual boot).  Here are some of the 
messages that FreeBSD has while it is starting up:
ad3:  WARNING - READDMA UDMA ICRC FAILED
Mounting root from ufs:/dev/ad0s2a
set root by name failed
ffs_mountroot: can't find rootvp
Root mount failed: 6

Then there are a couple more messages and it goes to this prompt:
mountroot>

What can I do to get this working again?

Thanks

/Brian