Had the same thing happen to my 2001 X5 3.0i - fuel was full and would not register - the dealer had to replace a faulty fuel sender. This may be just paranoi on my part but ever since then I don't try to overfill my car - when the pump automatically shuts off, I put the fuel cap back on - I remember somebody telling my that BMW's are sensitive to that - again that may just be a myth but have not had a problem since then - that was 2 years ago.