I just bought a new 15" MBP and Airport Extreme Base Station. I blugged a USB hub into it and 3 external hard drives into that. It will recognize 2 of them but not the 3rd. The only difference I can see is that the 3rd is a 2 bay enclose with 2 500GB's JBODed into 1 drive. The other 2 are single drive enclosures. Would that be the issue?