<p>Sometimes, my UIWebView will have a grey box over part or all of the content. I can't make heads or tails of why it's happening.  It happens regularly for certain content.</p>

<p>Thanks!</p>

<p>--Update--</p>

<p>It seems to occur when the webview is not immediately viewable on the screen -- ie i've got a scrollview, and the webview is below the fold.</p>

<p>--Update #2--</p>

<p>When I bring the content above the fold, it loads fine most of the time. There are still instances when the grey box is still showing up. The weird part is if i double-tap it, it finishes loading the content just fine.  bizarre</p>

<p>--Update #3--</p>

<p>Okay, so it seems to be that if my uiwebview has a height greater than 1000px, a grey box appears on the rest of the content below 1000px. A double-tap reveals the actual content.</p>

I have been dealing with this glitch as well, and have opened a bug report at apple. 
I would have commented above, but I don't have the 50 rep yet.
For anyone else encountering this glitch, send them a report, I included a full project demonstrating it, with a few screenshots from another app I am working on.
The more bug reports they get on a topic, the more likely they are to address it, apparently.
https://bugreport.apple.com/