On the Blackberry Bold 9900 running 7.1 Bundle 998 (v7.1.0.284, Platform 5.1.0.230) I am having a strange viewport related issue.
I am non-deterministically seeing screen.width alternate between 320px and 356px.
This affects the behavior of rendered content because I have a
<body>
<div style="width:100%">
</div>
</body>
that approx 50% of the time renders correctly (i.e. no horizontal scroll), but the rest of the time renders zoomed in and scrolls horizontally by 36px. Setting a fixed width on the body i.e. 320px causes the zoom issue to be resolved, but still has a white scrollable area on the right side.
Viewport:
<meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no"/>