Ok, I got Movable Type 3.2 working this morning. Looks like it was actually a problem with Firefox--it was using a cached version of the javascript files from my website. I had to clear my cache and restart Firefox to get it to use the new files I uploaded last night. Strange, I've never had a problem with Firefox using the wrong (cached) version of a file before. Reminds me of back in the days before IE, when Netscape was notorious for ALWAYS using cached files and it was sometimes a pain in the ass to get it to refresh from the web.