I should add that the starter on my GS had similar problems. I removed it and took it to the sole BMW agent here in Hong Kong .. they said "Leave it here and we'll check it out" ... the next day they called back and I went back to see them, to be told " ... erm, yes, that sometimes happens ... here's a new one ... "! It's been mentioned in some other threads and seems quite a problem.
I was VERY surprised to get another one gratis from the dealer.
Nick