Q:

How do I stop Firefox from closing my streaming jQuery ajax response? 

I'm a little new to comet-esque requests, so please speak up if I'm making too much work for myself and should be using a library or some other method. 
Basically this is my situation: I have a page that sets an <iframe> element's src attribute to a php script.  The PHP script streams the response with the following headers:
Connection: Keep-Alive
Transfer-Encoding: chunked
Content-Type: multipart/x-mixed-replace

This works famously in safari!  However, firefox closes the connection after a couple of seconds.  How do I fix this?  I've examined the responses for the script for both browsers and the responses are identical otherwise (up to the point that Firefox closes the connection.) 
Awesome update: Firefox hates the "Content-Type: multipart/x-mixed-replace".  Once this is removed it works in Firefox. 
Isn't there a better way to do this kind of thing? 

A:

The solution here is to send Content-Type: multipart/x-mixed-replace to Safari but not to Firefox. 
For reasons I don't fully understand, Firefox will disconnect from the server after a few seconds if this header is present in the response.  Firefox will handle a streaming response just fine otherwise. 
To implement this, I simply added a check for the user agent in the code as such:

if( preg_match("/Safari/", $_SERVER["HTTP_USER_AGENT"]) )  
    header("Content-Type: multipart/x-mixed-replace");

