Plazmic.com It's a downloadable theme editor. It takes a little work to get it set up on your CPU, but once it's done you can make your own themes. A simple one takes like an hour. To do something interesting it make take longer depending on how much editing or creating of pictures you have to do. You should check it out if you have the free time.
No, I just had to enter it when doing the initial down load. Once I had it on my computer there was no problem. Are you having the problem while on the BlackBerry website, or while trying to run Plazmic on your PC?