MPEG/VCD Scaling Problem

[Chandler]

When I play back MPEG-I full-screen, the image is not being interpolated anymore.  It's just resizing the pixels without smoothing them and it looks awful.

Higher resolution video is scaling perfectly (except for the chroma but that's a hardware limitatation).  Low resolution DivX is also being interpolated.  It's just the MPEG-I decoder.

When Windows XP was first installed, I know for certain that low resolution video was being scaled properly, but it seems to have stopped.

Is there a registry setting somewhere which will allow me to change the overlay mode (I think this is the problem).

OS:  Windows XP SP1
Video:  SiS 630S (SiS 305 equivalent)