I have a weird problem when playing AVI's in Windows Media Player 10. From time to time I get a diagonal "staircase" effect appear (as though, when switching from one frame to the next, only half the frame is updated, with a diagonally stepped line separating the two frames). I have only noticed this at fullscreen, although it may happen in windowed mode too. Does anyone have this problem? Are there any solutions. For info, I am using an AGP Radeon card, running at an interlaced resolution. The display frequency is 60Hz, and the source material is PAL 25fps. In my WMP settings, Video Acceleration is set to "use overlays". Are there any other settings I should use to avoid the "staircase"? Thanks.