Sorry for not answering for such a long time but it's exams season here in Greece (I' m a teacher
)... Yes, it's a graphics improvement at 2.6.29 -30 kernel (intel graphics)... But, with mintupdate, i still have the same problem, with 2.6.28 kernel too.
And something else.. After my last Gloria update (made manual) i cannot rotate the desktop cube with the mouse wheel any more, and cannot find the corresponding setting in compiz-manager. (It was an update about compiz in update packages).