I guess with 'pixelation' you mean that the animation gets kind of blurring /Unsharp? In that case I think the codec is the cause of your problem. I made several animations in Bryce and tried different codecs to get 1: a good quality, 2: a small file. I'm not happy at all with the codecs that comes with Microsoft's Windows 98/Me. They do a good job at decreasing the file-size but In my opinion the quality really sucks. I prefer converting the AVI-file to Mpeg, DivX or a quicktime MOV-file.