Time Machine Backups are Empty

Hey guys - I have this weird problem with time machine. I'm backing up and iSCSI target to an external drive (also an iSCSI target). Time goes through its whole thing and reports a successful backup but the backups are empty. A folder was created for the volume being backed up but there is nothing in there.

Some information

• 10.5.8 with Server App
• Volume is 6TB with about 3.7TB of data to be backed up
• Backups were successful at one point in time, one day the directory just started showing up empty
• I've verified that there is enough space on the backup disk to hold all the data
• ATTO iSCSI initiator
• SAN is an MSA P2000

What I've tried so far

Performed a "hard reset" on time machine

• disabled time machine
• unmounted backup volume
• /Library/Preferences/com.apple.TimeMachine.plist
• remounted backup volume
• added volume back into time machine
• reconfigured my exclusions
• manually ran a backup

Backups successful but directory is still empty

Also should mention that I removed the .spotlight file from the volume to be backed up. I just looked at the most recent backup attempt in console, it says "copying 0KB from <VOLUME TO BE BACKED UP>". there is 3.7TB of data in there!

Any ideas?

Thanks guys