Update on my publishing problem: I think it was related to our networked environment. Our "My Documents" directory is mirrored to back it up on a server, so it isn't really on our C drives. I think Captivate has a problem trying to publish from over a network.
When I moved my Captivate file to a directory actually on my C drive, the publishing problem disappeared. I just have to remember to copy the file to My Documents so it gets backed up on the network.
-K Petersen