My TiVo HD exhibited symptoms indicating that its internal HD was failing, so I bought a new, bigger one from weaKness. Install was painless and everything's worked well since.

That was about four days ago. Today, I tried attaching the external WD drive that had been attached before the internal HD swap. A few minutes after booting, TiVo recognizes that the drive is attached and says that it needs to do some stuff to it to make it work. I give it the go-ahead and it reboots. ...and subsequently repeats the same process over and over again.

What do I need to do to get my external HD working again?

Thanks,
Jeff