So far, 403-417 won't load my room, just my buddy list. So I moved on up... Tried 448, but I couldn't find the IMVUClient folder, even after a search of my drive. I couldn't find the .xml, either... But it ran great! I had all my furniture in my room. 449 is working good. I STILL can't find the IMVUClient, or even my application data folder. It should be right under my admin account name in documents and settings. But it ain't there, or in all users, or under guest. I'm stumped.
An interesting sidenote, I still have the latest version installed on my computer, it seems. I guess because you changed the file name, I'm able to have 2 versions installed. Pretty neat. Convenient, too!