Bluetooth audio cutting out frequently
 

I'm having a problem where I'll be listening to music over Bluetooth audio from my phone (HTC Glacier aka myTouch 4g), but every minute or so the audio will cut out for a split second and fade back in. My friend has the same phone and it happens to him in my car as well, but it works fine in his car's Bluetooth system. Any ideas what might be causing this and how to fix it? Thanks.