Okay I tried Jon’s and Roland’s suggestions first and it worked. AE choked through the render and eventually gave me what I wanted. But I will heed Dave’s warning about the freaky file formats in AE and try to avoid them in the future.
I do have the drive space right now, so I’m going to give Kevin’s suggestion a shot and convert my AVCHD files to one of the lossless formats first (in Vegas), then do the keying in AE, then render into the same file format.
Thanks again. You guys are the best!
Cuitla