I have the same problem and trying to find an answer...
My details: BMW 320d 2005 E90 Auto
Factory fitted BMW Professional Audio Sytem Non-iDrive
Every minute or so, the audio system jumps/skips, whilst playing CDs, Radio and via AUX.
The Bluetooth Telephone icon on the menu screen shows 2 dashes (--) instead of the phone icon. So you cannot connect/pair as I assume it thinks there is no bluetooth. This is the same problem...
I think both the above problems are linked. Google suggests could be amp / ariel / battery or bluetooth reset / loose connection problem?!
anyone with anymore info...