Originally Posted by mullethunter3
Sometimes the sockets (at least on the 5 series) good "bad". For what ever reason, the sockets get hot and melt a bit. It happened on my mother's car. Anyway, replace the bulbs with quality ones (Osram and Slyvania seem to work the best...).
Hope that helps.
The socket of my left front turn signal got messed up like that and it seemed to have the same effect. So yeah, check the socket.