If data-position="fixed" is used; pinch zoom not working on iPhone (iOS6)

If data-position="fixed" is used; pinch zoom not working on iPhone (iOS6)

Using jquery-1.9.0.min.js and query.mobile-1.3.0-beta.1.min.js

Noticed if data-position="fixed" is used (for navbar in my case), page cannot be zoomed using multitouch on iOS 6.

So had to avoid using fixed positioned toolbars. Any idea to overcome this issue?