Awbimmer: It's definitely a good idea to rip out the HU to check that the green cable is in the right black connector. Also check under the glovebox as mistryn has said.
Its quite likely that these two issues have caused your problems in my opinion.
2008 E92 335D SE
2010 E90 320D SE
1994 E36 318I SE
1996 E36 316I SE