I've had a more-than-50% failure rate with sandforce drives from three different vendors ordered in the last two months (5/9), they've been dead on arrival. I wonder if something is up with Sandforce at the moment?
I would say that your case is an outlier. I've had no problems with sandforce drives from OCZ and Corsair. And judging by recent newegg reviews on sandforce drives, many other people haven't had problems either.
To the OP: Stupid questions: try a different SATA power plug? Make sure its in an Intel SATA port? If its just not being recognized and it sounds like you've tried all viable solutions, you may need to just RMA it. Faulty drives from the get-go are rare from any vendor, but it does happen. If you RMA and the next drive doesn't work, I can pretty much guarantee that the problem is somewhere else...probably the motherboard then.
Main: i5-3570K, ASRock Z77 Pro4-M, MSI RX480 8G, 500GB Crucial BX100, 2 TB Samsung EcoGreen F4, 16GB 1600MHz G.Skill @1.25V, EVGA 550-G2, Silverstone PS07B
HTPC: A8-5600K, MSI FM2-A75IA-E53, 4TB Seagate SSHD, 8GB 1866MHz G.Skill, Crosley D-25 Case Mod