I am well aware of a few threads on this topic but I just got off the phone with HTC. The rep asked me to do a hard (factory) reset of the phone and see if that resolves the problem. I am not ready to do that at this point, and he said there was nothing he could do unless I was willing to reset first. In fact, he said they didn't have a lot of complaints about this at this time. So, please call HTC (or email them) if you have this issue. If enough people do, they will "look into it" and if the problem is similar to the EVO issue, maybe it wont be long for the software fix to come. I am not willing to do a factory reset because I have put too much time into getting my phone where I want it to be and this problem only effects when I try and use in car NOT plugged in (which I rarely do).