2 Firewire drives got errors since used with iMac C2D

Question

HI
i get this when i start Disk Utilities
Verify and Repair disk “Projects”
Invalid Volume Header
Checking HFS Plus volume.
Checking Extents Overflow file.
Checking Catalog file.
Start repairing it , says repaired but refuses to mount the drives!
And on the second drive i get this:
Verify and Repair disk “disk2s3”
Checking HFS Plus volume.
Invalid B-tree node size
Volume check failed.
Error: The underlying task reported failure on exit
1 HFS volume checked
1 volume could not be repaired because of an error
Anyone know a solution?
Both 750GB drives which never had these problems until used with this iMac a week ago.

Answer 1

So i repaired my Disk called "PROJECT"
Verify and Repair disk “Projects”
Checking HFS Plus volume.
Checking Extents Overflow file.
Checking Catalog file.
Checking Catalog hierarchy.
Checking Extended Attributes file.
Checking volume bitmap.
Checking volume information.
The volume Projects appears to be OK.
1 HFS volume checked
No repairs were necessary
However, it refuses to mount!
And when i run the Disk Utilities on the Volume, i get this still:
Verify and Repair disk “Projects”
Invalid Volume Header
Checking HFS Plus volume.
Checking Extents Overflow file.
Checking Catalog file.
Checking Catalog hierarchy.