Be sure the Program Monitor is set to to full resolution playback.
Thanks Jim. I'm on full resolution playback. Also any exported output will end up with jagged/pixelized edges on moving shots.
Post screen shots of the image, before and after, so we can see the problem.
Also list out the specs of your footage and your sequence, as well as the settings used for the effects on that clip.
Is GPU acceleration on or off? What model graphics card? What driver version?