Why do I get these smear like pixelation glitches in my video after exporting?

This is what the glitch looks like. I am using Adobe Premiere CS3http://gyazo.com/7b5681e63602702baf8ceba1bed13dd4.png?1357944961

I made a sequence using mp4 files recorded at 15 mbps, so they are high quality clips. I exported my finished video using H.264 (mp4) at 1080p and 12 mbps. I even tried using 2 pass as I thought the transitions i inserted along with the fast paced action of the game was causing smears. But even 2 pass didn’t fix it.

 

Any suggestions?

via Adobe Community : Popular Discussions – Adobe Premiere Forums http://forums.adobe.com/thread/1133744