Firefox 4 JS fails to send ~6th AJAX request while other browsers work as expected
<p>I'm using jquery to post a form back to the server and it works very reliably on all browsers except FF4 on an older Windows XP setup.  It reaches the point where the XHR should have been sent, but I never see the request in the server log.</p>

<p>The machine isn't mine, but is one of my Beta Testers.  It's been a consistent problem, but I'm not sure how to debug it.  He isn't a web developer, just a friend of a friend that happened to be willing to test a game for us.  If he restarts FF, it works about 6 more times and then it fails.</p>

<p>It's a facebook app, and there are other XHRs that Facebook is doing, so the 6th request is in my app.  My app is NOT a single page app, but uses 2 XHRs within this one page, one right after page load, and one about 4 minutes later.  I'm using setTimeout a bit, but otherwise, nothing else other than trapping keystrokes.</p>

<p>This same code works on a old G4 Mac running Safari 3.0 just fine, without ANY issues for hours at a time.</p>

<p>How do you troubleshoot something like this.  Not sure I want to try to get into a remote Firebug session....</p>
