In the latest issue of BMW Motorcycle Magazine, Jens Staebe, Head of Technical Support and Warranty at BMW Motorrad talks about this issue as being a 'clutch separation and shift shock' issue and goes on to say that there is ONLY one approved engine oil for the GS-W. That oil is Castrol Power 1 Racing SAE 5W-40, APL SL/JASO MA2, and it's expensive (go figure). Overfilling the crankcase must be avoided. He stated that, "We are familiar with isolated confirmations of this separation behavior of the clutch, which is why we are investigating improvements. If technical measures should be necessary, we will inform our commercial network immediately." Nothing in the article mentions anything about overfilled reservoirs.