help,can see only a square of the tv image (1 Viewer)

[bergsprekken]

Im using vista and coreavc. Floppydtv and "rikstv" in norway.
When I watch a channel in mediaportal client it looks like it is zoomed in on the picture.
The whole frame is filled, but it shows only a square of the whole image.. I have tried different zoom and modes but nothing changes it.