'TRANS PROG FAIL' message - could this be related to an LPG conversion?

What is your question?

I recently bought an '02 X5, the 3.0. I also had it converted to run on LPG afterwards. The conversion was fine but I have noticed the TRANS PROG FAIL message come on on starting the engine. It then goes away whilst driving and the car is mostly normal, though the gears are pretty harsh. Could the LPG conversion have caused this, or is it likely to be a coincidence?