[otrs] Customer Logins

I know I'm going to feel stupid asking this.... I'm having an issue with customer user logins. I have made user accounts for all of my company's customers so they can view their tickets. But when I go to the login page none of the customer user accounts I created work. It says I have an invalid username/password. I've checked to make sure I'm not doing something really dumb like misspell the name, and I'm not. I also looked through the FAQ and help manuals and can't find anything that has to be specifically turned on to make it possible for customers to log in. Anyone have any ideas? -Garren McKelvey