Hey,
I have a simillar problem. I just bought an US 07 335Xi E90 in Canada and the previous owner installed aftermarket angel eye halogens and housings. I drove the car home that night in a white out and the headlights are not exactly great. From what info I've found so far my car came with adaptive xenons. One symptom that I have that might explain your brights and is as a result of non adaptive lights being installed is no brights when stick is pushed back though the blue indicator comes on and stays on. I do however have brights when pulled forward and held. From what I've found this is because the pinout on the 7pin from adaptive headlights is slightly different from normal ones you can fix this by jumping wires.
See thread I'll post if and when I figure out if the factory set he gave me with the car fix my problems and If i find any other info.