video stutters after rendering

Hi,

I rendered a video (about 30 sec) and it stutters often in scenes with a bit motion and extremely in scenes with a lot of motion

23,98 fps, 1280x720 (goes for footage, comp and rendering) 

I use h264 

The bitrate doesn't matter. I tried it with a lot of different bitrates, it never worked. (from small to big)

Just 2 days ago I edited a similiar video and rendered it with the same settings and it worked. 

I rendered it once with MPEG4 and it didn't stutter, but the quality was terrible and a lot of thigns didn't match. 

Can anyone help out?

Thanks