How can I tell if my hard drive is bad?

I have a 1TB Seagate Barracuda that I am convinced is bad but per Seagate's Sea Tools the drive is good. I did the short test and also the 4 hour long test.

The drive is fairly new (purchased June 2009) but I am constantly running in to problems with it.

When I boot from this drive about 1 in every 4-6 times Windows goes through this 15 minute utility on a light blue screen where it deletes cache files. After it does so windows can boot from the drive. This has happened about 5 times so far.

I think the drive it good for the most part but it definitely has problems. It behaved this way on my old PC and it is on my new one also. So the MOBO, Sata Cables, Processor, case, and power supply have all been swapped with new hardware so these items have been eliminated as a potential factor. And the Primary drive operates flawlessly. Plus I have a new 650 Watt Corsair Power Supply so none of my hard disks (2) are underpowered.

Seagate's site says they reserve the right to charge you shipping if the drive tests good. Thus I am afraid to return it since SeaTools says the drive is good.

Does the Forum think this drive is good? Or are there other factors I am not considering. What should I do?