Can you use the Microsoft Windows XP Decoder Checkup Tool to tell us which decoder is assigned as the primary fopr your system and the version.
I am going to roll back to pre 91.xx Nvidia Forceware drivers. I 'm using a 6600, It seemed like a hardware issue the other night as the stutter got progressively worse and worse. I tried pausing and resuming to no avail BUT the last few times I have let a DVD play for a while, entered room to stuttering, activate my mouse (move it around), and the stuttering stops....totally bizzarre as I simply could get the stuttering to stop during an actuall movie viewing.
Stuttering occurring in both WMP & MC, but only after a while. I could try to use FFDSHOW to do decoding and see if using CPU instead of GPU would make a difference; I notice 75-80% CPU load with FFDSHOW as opposed to 25% CPU load with Nvidia Purevideo which loads up the GPU. This is a 6600 Gigabyte passively cooled card so I wonder if its getting way too hot; this may be a good test....or not.
DC