@Schlidel & mrg666:
I just sat in my car for about 30 mins to test A2DP audio, using Pandora. Tried turning the screen on/off switch away from Pandora (leaving it in background), pausing, skipping tracks etc. After about 15 mins of letting it run (listening to Shostakovich's 12th) I was ready to declare it stable.
Then, just as I was about to wrap it up, it suddenly DID disconnect from A2DP and swicthed to the phone speaker. The car still displayed the A2DP icon -- but apparently wasn't receiving any audio. I was unable to make it connect again other than by toggling BT, forcing the car to search again. Once it picked up I let in run for another 10 mins and had no problems.
(One other thing I found was, there is absolutely no way the screen will ever turn itself off as long as Pandora is running, regardless of whether Pandora is in foreground or background. And yes, I did try both Pandora's Conserve Battery settings. It's probably to help their advertisers, to which I am somewhat receptive given it's free.)
Maybe this is completely unrelated to the kernel and even dates back before the BT fixes mrg did. And maybe the reason Schlidel is seeing it more is because he listens for hours while I (at least) only test it for 30 mins. I still haven't tried to go back to earlier ROMs/kernels and see if it's any different. I'll see if I can find time for that this weekend.
In short: I too was able to reproduce the A2DP disconnect -- I know I am verbose