fb:comments scrollable under a fixed footer on iOS?

We are building a small web page that lives in a UIWebView in an iPad app. This webview has a fixed footer at the bottom and a scrollable div in the middle. Up until now we had a good solution for this, using iscroll4 to scroll the div. When that div contained only text and images, iscroll worked like a charm.

But when we add a fb:comments tag into that scrollable div, bad things happen. We've tried a number of different scrolling and/or fixed-position libraries including iscroll4, touch-scroll, and scrollability. None of them seem to work with fb:comments. The most common symptom is that any portion of the fb:开发者_开发百科comments that was below the original portion of the scrolling area does not show, even when scrolled into view. It's like the iframe size is fixed at the time FB expands fb:comments.

If this is a correct analysis, how can I get the iFrame to expand out to whatever size it wants?

Or, other suggestions as to what could be going wrong? I feel quite hamstrung as this is running in an iPad app in a UIWebView, and I have no handy developer tools like I do on Chrome (where the problem does not manifest).

Mike