1996 BMW Z3 Air Bag and Seat Belt Light

I have two problems that might be related, I hope you can help. The main fuse for the air bag kept blowing (15 amp fuse?) And it turned out to be the wiring for the drivers seat belt latch was shorting out.
I replaced both driver and passenger seat belt latches with new ones and that solved the problem with the fuse. The problem now is the air bag light will come on sometimes when I first start the car and stay on for about 2 to 3 minutes and then go out. When I check the codes it will say its either the passenger or drivers seat belt latch, which are brand new. I even tried connecting the old passenger seat belt latch and it still would give the same code. I have the code reader made by Peake, and the codes it gives me are number 18 & 19. The other problem I have which might be related is that when your driveing the car and you unlatch the seat belt should'nt the seat belt light on the insturment panel come on? I know the light is ok because it comes on when you first turn the ignition on. I think my problem might be with the air bag module, but I what to be sure before I replace it.