Topic: IE6 problems with ajax

Having tested on IE6 on my development server without problems, now the production version dies in IE6. Fine, of course, in Safari and Firefox, and in fact everything else I'm testing on.

The problem is that IE sees the AJAX request as downloads, and alerts the user about unknown file types via the standard file download dialog box. Again, this doesn't happen serving the site in a LAN (192.168.nn.nn addresses), with the port specified (:3000): no browser kicks up a fuss.

But when I NAT to view the site via Apache on port :80, IE sends up the complaint. I'm running my app on a specified port, on Lighttpd via Apache. If I specify the port (going directly to Lighttpd), no problems at all. If I try to view the site via :80, then IE complains. So it appears that something about the translation from Lighttpd to Apache is messing up IE

How do I ensure that serving my Rails App via Apache, changing port numbers doesn't cause this problem?

FYI : using textdrive shared hosting.