I have noticed a problem with StudioPress responsive themes on mobile Safari on my iPhone 4s IOS software version 5.1.1. (should be the latest version)
When I open a site in Safari on portrait it is fine - see
http://studiopress.com or
http://demo.studiopress.com/balance/
Then when I change the orientation to landscape the site grows wider than the viewing window and jumps to the right (I guess because it is trying to center the site on the viewing window).
Going back to portrait displays fine, however, then going back to landscape has the original issue again.
A client told me a demo site I am building did this which is why I noticed it in the first place.
It doesn't seem to happen on Mobile Chrome on my iPhone 4s.
I am reporting this just in case as it may be that I am doing or seeing something that no one is is doing or seeing, however, it seems worthwhile just raising a flag so someone can check as 2 people have noticed it.
Hope this helps.
thanks
Kirk