After trying the old 80 GB iPod, and it working mostly fine. I tried another brand new 160 GB classic. It's locked once in two days. That's not enough to be sure it shares the problem, but not a good sign.
I'm starting to think it's a general problem with the latest Classics. Apple has all but orphaned the Classic, so I don't expect a fix from them. Does anyone have a recent 160GB classic that _doesn't_ have this problem using the enhanced BT combox?
(BTW, the bluetooth static problem seems to have gone away with the latest BMW bluetooth update.)