Ok, so I've now managed to get some video displaying in mediaportal...  however, the tv I can display is very poor quality.  It looks kind of blurry, as though (guessing here) its only decoding a few lines and filling in the blanks, it's not even watchable.  I can however record perfectly, though mediaportal plays it blurry, Media player or VLC plays it perfectly.

In the television section of mediaportal configuration, my H.264 decoder reads as Cyberlink H.264/AVC decoder (Pdvd7).
Default zoom mode is set as Stretch - if I select Normal, all the video is compressed down to a narrow band in the middle of the screen.

Under DirectShow filter control, the H.264 decoder is set to use the hardware accelerator.  I've tried turning this off, but it makes no difference.

Video renderer is using VMR9, with all the boxes ticked, guassian quad selected as the filtering mode.  I've also tried changing all these, to no avail.

What could be wrong?  Is my computer maybe not powerful enough to handle it?  Though it obviously records ok, and the processor doesn't seem to work very hard at it.

The PC by the way is a dual 3.4 gig pentium, 4 gig ram and a nvidia 8600GTS video card.

James