From Frod
Shazam!!
Looking at your dxdiag and then looking at mine gave me an idea. I looked at my video settings in Windows and solved my stuttering: I set the video resolution in Windows at or above the game video setting (for me & you) of 1680X1050. Lo, And Behold! Stuttering stopped. Some kind of conflict is gone now (memory usage went back down too).
Many Thanks Maddafinga!
