2000 528i. I have the same problem. No matter if I have the belt on or not with no warning lights on the Instrument panel, i get the chime every time I accelerate from a stop. I take out fuse 18 if I'm just running around town but that also disables the speedometer and other gauges. I always use my seatbelt for those who suggest to "put it on" when hearing about the chime going off.