iOS Twitter integration - Authorize App keeps being displayed


I am currently working on an iPhone app with Twitter integrated so users can tweet from within the app. I am using oauth and everything seems to be working fine on the iOS side of things.

The problem is when a user tries to authenticate from within the app the authorize app view continues to popup as if the user has not been authenticated. I know the user has authenticated because in the UIWebView it shows the user logged in because of the avatar used for the account.

If I use the username/password of the account that has the Twitter app configured on it then the authorize app works fine. So in summary, the only user I can authorize the app on is the account that has the Twitter app. Any other user I cannot authorize.

What am I overlooking?

Thanks in advance!