Man - I feel ridiculous shaking my ipad and turning it 8000 times before it finally orients itself to the proper landscape / portrait setting. Is there a way to manually change the orientation, by hitting a button or something?
Seems like you have issue with the gyroscope inside the iPad. He's the one detecting when the iPad is turned.
Your better chance would be to go to an Apple Store if it's still under guaranty, maybe they'll find a problem and change it for you.
To answer your question, no, there's no hardware button to change the orientation. But you can lock it, and here's the 2 possibilities. If under