Video jitters on Cubase 8

hello,

I’m having a lot of video jitters on Cubase 8.
working on a film, having the video as h.264 (render in motion jpeg a codec),
everything is up to date and steel a lot of jitters. even when I cross the transport bar over
the video it jitters.
can please somebody help with this issue?

this is a big projects with a lot of vsts on it (Stormdrum, kontakt etc)

thank you