Stereo failing to play out of all speakers

After suffering a flat battery post a firmware update and playing with the Nav system with doors open far too long.

As described here: http://www.bimmerfest.com/forums/sho...d.php?t=677235

After charging the battery and taking the 2006 X5 E53 3.0 Diesel for a good long drive to reset the fuel computers, i have noticed the Speakers on the left side of the vehicle no longer work?

After reading i find it common to have a problem with the Radio Module adjacent to the battery.
Considering i removed and refitted the spare wheel yesterday, i thought perhaps i just knocked some wiring about, a plug perhaps.

Today i once again removed the spare wheel and visually check all wiring and plugs. At this point, i am not under the black plastic cover that houses the TV, Radio Module and GPS.

Trying the stereo again, i now have the rear left speaker working, but not the front. No matter what the "Balance" or Fadar" are set on.

While listening to the Left/Rear speaker by itself (as set by Balance control), i notice it fades away in volume, then comes back and can stop altogether.

Turning the ignition off then back to position 1 will once again get this left/rear speaker working.... yet no left/front.

I have read similar post elsewhere and the problem seems to be pointed at the Radio Module most times....
With either Repair or Replacement being suggested.

1. Was it the flat battery?
2. The charging process?
3. Pulling the spare wheel in and out?
4. Software update to 4-1/100?

Any ideas?

I really need to learn to stop playing with things that already work perfectly!

As yet i have not removed the cross brace and plastic cover over the Radio Module to check for a loose connection.