I had all the same symptoms with my Bf xrt and I narrowed it down to this. Before I load my tune I make sure that my mobile phone is switched off because I think the bluetooth conection was interfering with the tune. Once I load the tune I start the car, switch it off then re-load the tune a second time. this has sorted my problem as I noticed that some times when I loaded the tune the car would run better than other times, also I have noticed that it is a good idea to freashly load the tune every now and again as the car seems to have a mind of its own sometimes. Some of my side effects have been - Speedo not working or locking on speed, auto not changing , selecting nutral or locking in one gear or the other, trans hi-stalling at takeoff, trans not changing gears, all dash cluster lights coming on and going into limp mode. Just try loading your tune twice in a row as it fixed my problems, Cheers, mark.