Yes that's normal. You need to change it to be higher than that of Internet1. Higher metric means less preferred.
Also to answer your question about how to back it up... I recall on my WRT54GL there was an option to backup your configuration... oh... wait... I think it was just the configuration not the actual firmware. Never mind and sorry to send you on a wild goose chase. Anyway, it looks like the 1.04 image was a rogue from all the reading I've done so you might be better off with the 1.01. This is also a fairly new router so with patience you may luck out and a release of dd-wrt would be available for it.
Casey