Found an old closed thread that gave http://support.microsoft.com/kb/977178 as the solution to the problem - but that hotfix won't install to an SP1 machine. Looking for a solution for Windows 7 SP1. The drive in question is one of the newer Seagate BarracudaLP drives. Seagate was no help, and MS want's me to pay them $200+ to even be able to ask them about it (with no actual help guaranteed for that money).