Has anyone else experienced issues with how call waiting affects the Treo 600? If a call comes in while I am already on a call, I can answer it/ignore it, etc...but if I do answer it, talk and then flip back to my original conversation, the screen never clears from that last call. Because of that, I can't seem to get back to the controls I use during a call such as mute. Anyone run into this and/or might be aware of a fix?