I am definately gonna try this bluecat. I have the exact same scenario as 5 litre eater, and i tried the MAF VE Error thing before which threw things out just like trying to tune with AFR Error.
One thing i did notice - changing the VE values threw my AFR out even though i had "disabled" SD and was running in high speed. So VE is always there...I am sure if I get the VE right I would have to change the MAF cal as the MAF cal is probably compensating for the wacky VE...