problem with passportjs

gistfile1.js

passport.use('twitter', new TwitterStrategy({
    consumerKey: config.tw_consumer_key,
    consumerSecret: config.tw_secret,
    callbackURL: config.base_url + '/twitter/callback'
}, function (token, token_secret, profile, done) {
    // twitter callback comes here to get the twuser obj
    log.info('got twitter profile:', profile);
    var TWUser = require('../models/twuser');
    // find the twitter obj if it exists
    db.findTWUser({providerid: profile.id}, function (err, doc) {
        if (err) {
            done(err, null);
            return;
        }
        var twuser;
        if (!doc) {
            // create a new twitter obj
            twuser = new TWUser(profile, token, token_secret);
            db.saveTWUser(twuser.pack(), function (err, doc) {
                if (err) {
                    done(err, null);
                    return;
                }
                twuser = TWUser.unpack(doc);
                done(null, twuser);
            });
        }
        // unpack doc into obj
        twuser = TWUser.unpack(doc);
        done(null, twuser);
    });
}));

passport.use('facebook', new FacebookStrategy({
    clientID: config.fb_appid,
    clientSecret: config.fb_secret,
    callbackURL: config.base_url + '/facebook/callback'
}, function (access_token, refresh_token, profile, done) {
    // facebook callback comes here to get the fbuser obj
    var FBUser = require('../models/fbuser');
    db.findFBUser({providerid: profile.id}, function (err, doc) {
        if (err) {
            done(err, null);
            return;
        }
        var fbuser;
        if (!doc) {
            // creata new fbuser obj
            fbuser = new FBUser(profile, access_token);
            db.saveFBUser(fbuser.pack(), function (err, doc) {
                if (err) {
                    done(err, null);
                    return;
                }
                fbuser = FBUser.unpack(doc);
                done(null, fbuser);
            });
        }
        // unpack the doc into the obj
        fbuser = FBUser.unpack(doc);
        done(null, fbuser);
    });
}));

var app = express.createServer();
app.set('view engine', 'jade');
app.use(weblog.logger);
// to catch favicon.ico; should improve
app.use('/', express.static(__dirname + '/public'));
app.use(express.cookieParser());
app.use(express.bodyParser());
app.use(express.session({
    secret: config.SESSION_SECRET,
    store: session_store
}));
app.use(passport.initialize());
app.use(passport.session());
app.use(express.errorHandler({ dumpExceptions: true, showStack: true }));
app.use(app.router);

app.get('/facebook', passport.authorize('facebook', {
    scope: 'email'
}));

app.get('/twitter', passport.authorize('twitter'));

app.get('/facebook/callback', passport.authorize('facebook', {failureRedirect: '/reg'}), function (req, res) {
    weblog.error("successful fb callback, req.account:", req.account);
    res.render('reg.jade', {
        account: req.account,
        provider: 'fb'
    });
});

app.get('/twitter/callback', passport.authorize('twitter', {failureRedirect: '/reg'}), function (req, res) {
    weblog.info("successful tw callback, req.account:", req.account);
    res.render('reg.jade', {
        account: req.account,
        provider: 'tw'
    });
});

app.post('/register', function (req, res) {
    log.info("reg post, req.body:", req.body);
    var User = require('../models/user');
    var FBUser = require('../models/fbuser');
    var TWUser = require('../models/twuser');

    // at this point we have the user info in the body
    var user = new User(req.body.email, req.body.first, req.body.last);
    var findFunc = null; // finding the twuser or fbuser is the same process, this is the db function to find it
    if (req.body.provider === 'fb') {
        findFunc = delegate(db, db.findFBUser);
    } else if (req.body.provider === 'tw') {
        findFunc = delegate(db, db.findTWUser);
    } else {
        res.render(500);
        return;
    }
    findFunc({providerid: req.body.pid}, function (err, provider_doc) { 
        log.info("inside findFBUser");
        if (err) {
            log.info('failed to find the provider doc:', err);
            res.end(err);
            return;
        }
        if (req.body.provider === 'fb') {
            user.fbid = provider_doc._id;
        } else if (req.body.provider === 'tw') {
            user.twid = provider_doc._id;
        }
        // save the user
        db.saveUser(user.pack(), function (err, doc) {
            log.info('user saved, doc:', doc);
            if (err) {
                log.info('error:', err);
                res.end(err);
                return;
            }
            user = User.unpack(doc);
            if (user.hasError()) {
                log.info('user error:', user);
                res.end(user._err);
                return;
            }
            // save the password
            db.setHashedPassword(user, req.body.password, function (err) {
                if (err) {
                    res.end(err);
                    return;
                }
                req.user = user;
                log.info('successfully created account:', user);
                res.redirect('/');
            });
        });
    });
});