Looking at the m11x Driver on the Dell support site, the date is 6/10/2010.
Any hope of Dell ever refreshing and official release of this driver past the initial release version?
Don't know ... you can always hope 😉
I've been using the stock NVIDIA drivers for my M11xR2 (260.99 e.g. from here: http://www.nvidia.com/Download/index.aspx?lang=en-us) without any hassles. Of note these haven't been updated since around October 2010 either I think.