Before sending the rebate out I called Maxtor and they said that I had to send the top part of the UPC. It was kind of confusing because I was about to send the bottom portion that said "Proof of Purchase". What they wanted however was the top part with the barcode #754921025671. I sent mine in a week ago so I guess I'll have to wait and see what happens.
By the way, I got the HD for $119 from Office Depot, and the controller card from Onvia last Dec. for $42 - $10 coupon.