RRAS rejecting outbound packets on LAN

Does anyone know why win2k server routing and remote access would be rejecting outbound packets from LAN clients? My win2k server has worked flawlessly up until recently. We applied a couple of the new hotfixes and now it blocks outbound packets to places like yahoo mail logon. It will let users get to the logon page but will not load the page after they enter their username and password. The server can get anywhere but the LAN clients can not. Any ideas?