I got a nice reply back from htc and I have to agree with them. I did some more testing today and my htc works with MS sync, my jawbone headset, going to test it tomorrow on a lexus navigation that runs an ecplise series. So far all fingers point to pioneer. here is the msg back from HTC
We understand that it is important you receive all the information to best utilize your device. When it comes to Bluetooth on our devices, if it connects and you are able to talk, then it is working. Any further features, sounds, etc. are on the headset’s side. The options that our device provide are either “hands-free†or “stereoâ€. Neither of these determines if the headset will ring or not, unfortunately. I would suggest contacting the manufacturer of the headset.