If you're running IIS 6 (Windows 2003+) and ISA 2000+ on the same box, and you want to publish the webserver, you should check this out:

IIS 6.0: Setting Metabase Property DisableSocketPooling Has No Effect

http://support.microsoft.com/kb/813368/EN-US/

How to disable Socket Pooling

http://support.microsoft.com/kb/238131/EN-US/

Long story short:

1. Go into inetpub/adminscripts folder and "cscript adsutil.vbs set w3svc/disablesocketpooling true" does nothing.
2. So, get to a DOS window, and do a httpcfg set iplisten -i x.x.x.x (where x.x.x.x is the IP you DO want HTTP.sys to listen on).  You'll get a "... completed with 0".  That's normal.  Now restart web service and/or the box if necessary! ("net stop http /y" and then "net start w3svc" and any other dependent services you have installed.)