httpd processes won't die since upgrade to PHP4

Hi All :)

I have a problem with the following code (sorry if this seems like a bizarre
thing to do):

<?php
    while(true)
    {
        mysql("UPDATE A RECORD");
        echo "Some stuff";
        flush();
    }
?>

When the user closes their browser the associated httpd process doesn't die,
and the while loop continues to run.  Obviously after a while the number of
httpd processes becomes large and ultimately causes the server to crash.

No suprises there you might say, however this has only been a problem since
I upgraded from PHP3 to PHP4.  I'm running Apache 1.3.12 on RedHat 6.1.  Any
ideas anyone?

Thanks in advance,

Chris