When running php as an isapi filter, php connects and works properly, but does not reuse persistant connections so that each page view results in many, many open connections to MySQL server, which ulitmately results in errors because of too many connections.  We're connecting with code such as this:

$db_link = mysql_pconnect (DB_HOST, USERNAME, PASSWORD) 
		or die ("Could not connect to database");

Where DB_HOST, USERNAME, and PASSWORD are defined as constants. The php version is 4.4pl1, installed with the windows installer, using the php4isapa.dll from the zipfile.