Saw this a lot and the fix takes all of 1 minute:

Take a screw driver and carefully remove the spring that the door hinges on.

All you have to do is flip the spring upside down and reinstall. Yes, your spring is upside down, but do you really care, and do you want to pay BMW for a new spring?

Problem solved on mine since '02 and I did it on a fellow 4ngiefest car yesterday. I know this works on E36s, but I'm sure other models apply.