hi I recommend you check out the tutorial on animations in Bryce at http://www.brycetech.com/ my initial idea would be that you arent using compression, or are using a bad one (one that doenst decompress quickly). to play uncompressed files at full screen takes a fast computer. I have a 500 mhz processor and an ultra DMA hdd so I can play 640x480 at 30 fps uncompressed without stutter...but many computer cant..so you have to compress good luck BT