I don't seem to have found others with this same problem. I just purchased an N800 and immediately flashed to OS2008 (2.2007.51-3).

I now just got a Stowaway bluetooth keyboard. I've been able to pair it successfully (using all the wonderful help in this forum). But, when I use the keyboard the following happens:
the bluetooth icon turns blue
the blue LED on the N800 flashes 3 times
the N800 reboots

The behaviour is quite consistent.

Any places where this newbie can start to look?

TIA!