Bumping this up - as a feedback.
I had the same damn GM5 issue on my E46 - Sent it to Scott in the States. Cost me 120 dollars all in. The module works like a charm. I was thinking of getting a used one from the parts guys in the GTA but the issue there is that you dont know if it will run into the same problem, which means you pay for the used part and then may have to end up sending it to Scott anyway!
His service works great - no programming needed, I just plugged in my repaired module now the car locks and unlocks perfectly - it was like 35c the last few days and the car was sitting out in the sun for hours, it unlocked perfectly so now I dont need to carry my girlfriend in through the window anymore