I have been experiencing this issue with Radio Paradise's AAC streams (radioparadise.com) since upgrading to a Galaxy Nexus (4.0.4). MP3 streams do not exhibit the issue. It is not the wifi power management issue that you suspected because I tried a custom kernel that has an option to disable that and the issue still persists. The internal streaming engine works fine though, so that's a huge plus.

Unfortunately, 2.1.8 update has broken this for bluetooth controls. Even after setting the Media Controls option to off, when sending the bluetooth play command (while having winamp open and set to control audio functions), xiia live starts up and the commands never reach winamp.