Thanks to Ben Nadel

Firefox had been exhibiting an undesirable behavior on pages that used our javascript module, jquery.rdbhost.com. The module, under Firefox, would function correctly, but never seemed to detect that data reception had completed, but would show the busy spinner and 'loading...' indicators.

I googled in futility, I asked on stackoverflow, not constructively.

Branko Vukelic cued me to read Ben Nadel's blogpost on just that topic, which explained why Firefox was behaving that way.

It seems that Firefox acknowledges that an iframe document was completely received only after the onload handler returns. If the iframe is deleted from the DOM within the handler, Firefox never detects completion. The solution Mr Nadel suggested, and which I used, is to use the javascript timer to call a deletion function to run after a brief delay. This allows the handler to return while the iframe persists, but does not let the iframe linger around.

The fix has been pushed to the github repository for jquery.rdbhost.js, so feel free to grab the latest version.