Sorry for some irritating and "wrong" claims :
I wrote Splinter Cell 4 doesn't mount because someone (using bw5mount.dll 1.1.0.0) at our forums reported that.
I've now tested Splinter Cell 4 by myself and here the B6T mounts just fine.

So finally the only title i know where various people say the B6T doesn't mount is C&C Tiberium Wars