I have the same problem, as well. I'm on a Verizon HTC Touch Pro with the
Silence+Mighty ROM. My headset is a Jabra BT620s, and my media player of choice is CorePlayer, with the appropriate plugins enabled ( HTC WMControl, or something along those lines). The previous/next track buttons sometimes work, though still open up WMP. The play/pause button only opens up WMP.
I tried to use the file above, but it froze my phone on startup after soft reset, thus forcing me to do a hard reset. Any advice on this would be greatly appreciated.
Thanks!