OK... so here is my code:

twitterEngine = [[MGTwitterEngine alloc] initWithDelegate:self];    
    [twitterEngine setConsumerKey:CONSUMER_KEY secret:CONSUMER_SECRET];
    accessToken = [twitterEngine getXAuthAccessTokenForUsername:profile.twitterUserId password:profile.twitterPassword];
    NSLog(@"Access token: %@", accessToken);

the console shows the access token returned just fine (so it seems to work) eg. Access token: C8A24515-0F11-4B5A-8813-XXXXXXXXXXXXXX

but instead of accessTokenReceived method being called next on my delegate, it calls requestFailed with a 401. How can I be getting a 401 unauthorized and getting an access token back from the method call?????