Video pixelation

Has anyone had problems with this in V8? I never experienced this with my version 6. I am doing a wedding video, and when I pan the camera, you can see pixelation, or stuttering in the background (not the subject). Does the quality degrade everytime you render? This I was wondering also. I took the rendered file, and opened it up in Adobe Soundbooth to clean-up the audio. I burnt it to a dvd, played it, and several times within a 5 minute period, there were flashes of red on the video, as if there had been something like a .5 sec red clip on the timeline or something. I do not see the first problem or this one when it is played back on the computer, from the hd.