1998 523 E39 Electrical problems

I have been experiencing strange electrical problems with my 1998 523 E39. The radio display goes off intermittently and the brake lights go on, along with the interior lights. At the same time the cruise control stops working as does the drivers vanity mirror light. Then normally after between 30 seconds and 5 minutes the airbag light comes on and all the above start working. It is very bizarre!! This sometimes happens when starting the car or intermittently when driving along. The car will start correctly with all the right lights on by turning the ignition repeatedly until the problem fixes itself. I guess the ignition switch could be the problem - anybody got any ideas?:banghead: