Sorry I can't actually help but I have the exact same things to report: jawbone icon bt headset acts the same way. Rings only once (actually announces the phone number of the caller, but does it only once). On the plus side, I also can activate voice dialing from the headset while the phone is sleeping in the holster. I didn't know if that was a Motorola thing ontop of 2.2 or if it was the Jawbone Icon letting me do it. Since you have the slightly older Jawbone 2, I'm thinking it is part of the Motorola skin. I just am surprised more people haven't mentioned it!
Hopefully someone knows a way to get the bluetooth headset to ring more than once. If not, I really hope the 2.2 update changes this....
Subscribing....But at least you know you are not alone.