I've seen a few posts about Networx reporting more traffic than is registered by an ISP for those who have incorrect settings in the program, but mine is the other way around. I've been logging traffic for a day or in the "applications" tab for all users combined. Only one user (Win XPSP3) is running on one PC connected via WiFi to a WRT54G, which connects to our ISP via a radio modem.
The traffic reported by my ISP is roughly double that reported by Networx. There is nothing else connected to the WiFi apart from the 1 PC.
Any ideas why this might be?