Before MR: Using the a cable plugged into the headphone jack I can connect my Treo to my car stereo(for playing music and audiobooks) and still use my BT headset to make/take phone calls.

After MR: If I connect my Treo to my car using the headphone jack it prevents me from using my BT headset for phone calls.

I found this thread in the 755p forum, but since the same problem happens on the 700p+MR I thought I'd ask the same question here:

I've checked/unchecked the "Always rought call to Hands-Free" setting in the Hands Free section of Preferences to no effect.

This is a showstopper issue for me because I spend over an hour driving to/from work each day and listening to audiobooks is the only thing that keeps me same.

If the 755p has the same problem, I figure I'll either need to have Sprint replace my 700p with a pre-MR version (and be forever doomed to lags and other problems) or try to get a 755p and hope that they eventually fix these issues in the slim chance they fix the problems in a MR for the 755p (this time next year???).