SA_OAuthTwitterEngine login keyboard doesn't show after first launch

I'm using the SA_OAuthTwitterEngine to integrate Twitter into on of my iPhone apps. Loggin in and sending tweets are working fine. But, when I completely terminate my app so it will start up from the beginning, I can't login again using the SA_OAuthTwitterController because the keyboard will not show up. The input field also doesn't respond to the Mac keyboard when using the simulator.

I've searched for similar problems, but they don't help me out. I've found a lot of similar problems, where calling makeKeyAndVisible for the app delegate window solved it. This doesn't work for me. If I set the modalview's alpha to .2, I also don't see the keyboard behind the view controller.

Weirdest thing is that everything works after a fresh reinstall for as many times as I want, but after I've terminated the app, the keyboard doesn't show op anymore.

Can anyone point me 开发者_运维百科in the right direction?

Thanks in advance!