Hi Cody,
Thanks for the response. I changed the RT to Unlimited and that seemed to do the trick. When I had the RT on Safe, ‘render selection’ wouldn’t render the dissolve and I had to chose render all, which took forever. So now that it is on unlimited, I can view the dissolve without rendering at all, although the ‘render all’ still takes a few hours for a 10min prores 422 HQ sequence, which may just be because I am running FCP 6.0.6 on an old 1.8GHz PowerPC G5 with 4BG of DDR SDRam on MacOSX 10.5.8.
Thanks!