I notice that it is now SR4 is now available. I would make sure that you trial it on a development server (as with any release) before rushing it out as I have heard that there are some changes to Set Analysis around tightening up the rules around when different quote marks are used. This could affect values presented by existing documents.
If you use Set Analysis then regression testing is essential.
I have this problem too. On opening a document from an IOS bookmark on ipad/iphone the session hangs while displaying 'Loading....' in top right corner of screen. Worked ok before installing IOS7. Have upgraded QV server to 11.2SR4 which supports IOS7, but get the same result. Does anybody know if there is something else I need to configure?