I have seen some glitchiness on my 2005 GS, too.I am interested in how many members have experienced problems with the fuel gauge sensor. Did BMW acknowledge the issue with it?
My GS1200A 2010 had the sensor replaced three times in a five month period in 2013. My brother, who was the first owner, gave up taking it back even though it was still under warranty. The sensor was not redesigned until about 2013 with a different type.
I contacted BMW Customer Service to ask their opinion on the design of the sensor. They were unable to express an opinion but said that because of the age of my bike they could not help.
I believe the fuel gauge sensor was NOT FIT FOR PURPOSE and therefore time limited BMW warranties do not apply. I am interested in other members experiences of speaking to BMW about this known issue.