This is the scenario I mentioned in the other thread, where my external 
Bluetooth dongle is now working better than my laptop's internal device. 
My laptop has the following:

0a5c:2101 Broadcom Corp. A-Link BlueUsbA2 Bluetooth

Playing sound to my A2DP headset works fine, and so does Bluetooth mouse 
input. But if I try to do both at the same time, mouse movement pretty 
much kills the audio, and I get long periods of silence. The audio 
resumes when the mouse goes into sniff mode, skipping several times to 
catch up. Then it dies again when I move the mouse. If I switch off the 
mouse's power switch before it goes into sniff mode while playing audio, 
the audio doesn't come back until the link to the mouse times out.

I'm attaching /proc/bus/usb/devices. I also made a log with 'hcidump -X 
-V', but since it's 804k compressed, I put it on some webspace rather 
than posting it to the mailing list: 
http://xyzw.org/files/hcidump-mouse-a2dp.log.bz2

To make the log file, I killed bluetoothd, started hcidump, then 
restarted bluetoothd. I then moved the mouse, authorized it (I guess 
having to do that is the BlueZ 4.29 issue mentioned on this list), and 
played some music to the headset. A few times during the music, I moved 
the mouse and triggered the breakup. This log doesn't include the test 
where I turned off the mouse while playing audio.

This is with the latest bluetooth-testing kernel.