Port forwarding suddenly stopped working

["Rifleman" <dave@xxxxxxxxxxxxxxxxxxxxx>]

Hi.
I am running an HP Mediaserver with Windows Home Server.
Router is a Netgear WNR854T which is UPnP compatible.
ISP is virgin media and I'm on the XL package.
I use Kaspersky Internet Security 2007 but disabling this doesn't solve the 
problem.

The HP server requires port forwarding to be set for ports 80,443 and 4125.

All of this was working fine, I could access the HP Server from work no 
problem.
However, a couple of nights ago the HP Server started giving warnings that 
port forwarding was now not working.
It says that the router is not accepting Web site connections or Remote 
Access connections.

Have tried reconfiguring, resetting router , cable modem etc but nothing 
helps.

Anyone have any ideas ??