getting bad exception while linking with twitter

i am following link (http://aralbalkan.com/3133) for integrating my app with twitter. I followed each and every stepp provided in this link, but i am getting the error in gdb :

 2011-08-04 17:33:32.037 XAuthTwitterEngineDemo[5533:1f0b] access token did fail ***************

and give bad exception at this method although i am providing my correct username and p开发者_JS百科assword. here is my code

- (void) twitterXAuthConnectionDidFailWithError: (NSError *)error;
{
    NSLog(@"Error: %@", error);

    UIAlertViewQuick(@"Authentication error", @"Please check your username and password and try again.", @"OK");
}

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Your provided token or secret key is invalid. Verify it again and also check the type of access your application is having.

Modified:

From here, you will able to follow the steps to have authentication.