We are using IE8 to automatic pick up the proxy configuration via DHCP. However, we've updated the PAC file hosting with a new file / different name and updated DHCP accordinly. However, majority of clients are still requesting for the old PAC file as I can see this via the pacd_logs. I've restarted the DHCP services, disabled proxy caching in IE8 and still no luck.
Any idea what would be causing this?