After signup, first login attempt fails

I used the signup and login code from the hybrid friends app template. Seems to work fairly well, however after a new user registration, the first attempt to login with the new account fails. second and subsequent logins work fine. At first I thought the backend system wasn't creating the account fast enough, but that does not seem to be the issue. Has anyone else run into this? (Function below)

// Register user after required fields (username and password) are validated in Backend Services
        var signup = function () {
            Everlive.$.Users.register(
                dataSource.Username,
                dataSource.Password,
                dataSource)
            .then(function () {
                app.showAlert('Please login now to begin using AppName.', 'Registration Complete');
                app.mobileApp.navigate('#welcome');
            },
            function (err) {
                app.showError(err.message);
            });
        };