Rear air bag question

[sandiegoX5]

I have a 2002 X5. I am the second owner and have owned it for the last three years.

Although I did not pay much attention to them, I have bright orange/red BMW OEM stickers on the rear door jambs which say "side airbag non-operational."
The X5 is no longer on warranty and I go to an independent BMW service garage.

Two weeks ago I had to have the right rear window regulator replaced. When they put the door back together, they hooked up the airbag (which apparently not been hooked up previously) and the SRS system would not reset. They got a reading that the bag was not operational. This has completely confused them.

The garage had not seen the orange/red BMW sticker before. I did find a post on this board in which the stickers were mentioned by another owner, so I don't think my vehicle is unique. Nevertheless, my garage is at a loss beyond unhooking the airbag and resetting the system, leaving the rear bags not operational.

Before I have them do that, I was thinking maybe it is time to hook up all of the airbags (left rear is still not) and have the system reset if that is possible without a great deal of expense. Is this possible? Has the garage overlooked something? Will it make a difference (which would allow the SRS to reset) if the left rear is also hooked up?

Any help would be appreciated. Thanks.