There seems to be an issue with the app not rotating when my iPad is in portrait mode, with the home button at the bottom and the camera at the top. However, rotation works fine in all other directions - landscape and portrait (when the camera is on the bottom and the home button is on top).
I'm unsure of what could be causing this problem.
Just as a side note, the app is built using HTML5/CSS3 and I am using an iPad 2.