Hardware Acceleration and Digital Artifacts

[msuplantdoc]

I have a new PC with Win 8, Intel I7 latest generation, 24 gig of RAM, Invidia GTX 650 TI. If I turn on all hardware acceleration choices (non are grayed out), processing is very quick. However, some clips in the final movie will exhibit digital artifacts or drop outs visible as blockly, blotches of color (usually green) that flash on the HD TV. There is no evidence of any problems when the clips are played back from the camera direct to the HD TV. Even the copied files played from a flash drive through a WD media player are fine. The artifacts are sporadic but frequently occur after a transition. Re-rendering the movie will change the occurrence of the artifacts to a minor degree but they still seem to occur with the same clips. Rendering the movie with accelerations turned off seems to fix the issue, but negates the higher end hardware. Files are AVCHD, full HD at 30P and 23 mbps from a Canon Camcorder. Any ideas or suggestions to fix this annoying problem. thanks

Greg