Nostalrius Begins - Quality wow vanilla realm (1.12)

Like the title says, when I launch the game, my mouse freezes and won't move. I can log on using <tab> to move between user name and password, but cannot select language or realm afterwards. I also cannot change my resolution settings or anything. If I Alt+Tab out of the game, my mouse works fine. I've never had mouse problems before this.

Any suggestions?