Problem loading AJAX content only in IE

[ifedi]

Hi guys,
Kindly spare a moment to look at this page: http://gottkann.com
Most of the page content is designed to be loaded by AJAX (mostly jQuery .post and .get) on clicking the menu links on top and to the left. Problem is: after A SINGLE SUCCESSFUL loading, nothing else happens in IE (I've tried v7 and v8), and only 'Home' seems to do anything.
All other major browsers seem to be doing just fine. And to complicate matters some more, this problem with IE ONLY APPEARED after uploading to shared webhosting, since IE was working perfectly well on localhost testing machine.
I'd greatly appreciate anyone's insight.
Regards,
Ifedi.

[ifedi]

Hi folks,
I obtained one DebugBar which I installed on IE. With this, I could monitor the HTTP traffic (a little like FF Firebug). With this, I noticed this returned content each time IE went 'silent':

<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<html><head>
<title>406 Not Acceptable</title>
</head><body>
<h1>Not Acceptable</h1>
<p>An appropriate representation of the requested resource /aj/sec_contents.php could not be found on this server.</p>
<p>Additionally, a 404 Not Found
error was encountered while trying to use an ErrorDocument to handle the request.</p>
</body></html>

I really do not understand this error 406 that well, particularly why it should play up NOT with the first request, but with subsequents!

Thanks as I wait an trudge!

Regards,
Ifedi.