I was just playing around with a trivial multi-touch test script in MOAI when I noticed some odd behaviour apparently related to screen orientation. I'm displaying the performance and step values from MOAISim on the screen and while i was poking and swiping, i accidentally rotated the device, and the framerate dropped to about 44fps as reported by MOAISim, which is also consistent with the noticably jerkier touch events I was getting at that time.
If I rotated the device back to the original orientation, fps went back up to 60 and input became smoother again. I could understand if this was an optimization sort of thing, in that certain orientations maybe need more work for doing the rotation, however... I reproduced the problem several times, and the orientations in which the framerate drops may be different every time. If I just keep rotating the device, eventually one or more orientations will begin rendering at 44, and then I can rotate back to a 60fps orientation and it's all good again... back and forth. Sometimes they're all good, others any one or more of the 4 orientations might exhibit the slowdown.
iPhone 4 running iOS 5.1.1 and using the latest packaged build of moai sdk