What output are you using? RGB or HDMI? What TV/monitor. It seems to be a hardware setup issue rather than Xbian.
Can you provide the xbmc.log as stated in "Read before you post" and a little bit more of what the problem is? Youtube is not that useful unless you know what you are supposed to be looking for.
If possible (and legal) can you provide a part of the movie so we can test on another machine to see if we experience the same issues.
sorry for not reply on the post (family issues) HDMI is the output and TV is old pc monitor (hav to check better in the morning). little tired. now but it is so funny no problem with later version of xbian only beta 2. I think mayby it is relate to some settings in xbmc or .. oh i but that xbmc soon is i get time to do that .