Bluetooth A2DP audio occasionally drops out for a second on custom ROMs
I have a Galaxy 2s with this exact problem but I wonder if I might offer a suggestion as to what could potentially be the cause. I have no idea how to fix it but I’m hoping that what I share here might help someone who knows more about the way these things work to be able to solve the problem.

I have spent much of my career working in Broadcast Radio, the problem I have heard my phone have with audio dropouts followed by either a ramp up of volume back to the previous level OR an audio dropouts followed by a momentary slight speed shift in the audio playback (sounds a bit like an old cassette recorded when the batteries are starting to fail) many people would probably not notice the later problem because it is very subtle and you have to know what you’re listening for. 

Anyway, I believe this could be caused because of a lack of word clock sync between the phone and the bluetooth receiver. I say this because there have been times when I have had digital audio devices such as CD players that are connected to an audio console or digital amplifier and with both devices free running in terms of their clock synchronisation exhibit almost exactly the same symptoms. 

You see all digital audio devices require that the audio data be put into frames much the same as regular Ethernet data is transmitted around a network is put into frames, however in order for the audio to be at the correct pitch and speed generally speaking both the playback device (Phone) and the receiving device (Bluetooth receiver) need to have the same word clock, otherwise you end up with the two devices running freely and the audio frames wont by in sync.
Depending on the Error correction implemented (sample rate conversion) on the receiver you can get really odd audio results. I think that this is what is causing this problem. Basically the Bluetooth receiver and the phone aren’t in sync so every few minutes you get a drop out. 

It doesn’t seem to happen when you are talking on the phone which makes me think that when you have a call connection as this is bi-directional, the phone is probably synchronised to the Bluetooth device word clock. But when you are listing to music the connection is mono-directional so there is no sync. 
Anyway just a thought. Maybe someone out there who understands the way these units synchronise can figure out a fix.