Larry, to my knowledge, that was only a problem with the K-series (although I'm sure it crept up in the very early days of the R-series back in the 1920's as well. Kind of funny that BMW would have that kind of problem after a lifetime building almost only engines that laid on their sides (the only difference is that the K had all the pistons "boxing" in the same direction instead of opposite like the R's)
To me, gravity would be pulling the cylinders to one side (the bottom), but BMW has a good rep so guess it doesn't matter.
They do make a 650 single though, the F650, which gets pretty good reviews as well.
