kam_61, the issue you have is to do with the Firewall on XP SP2 which is most likely turned on on the server. Please install v4.0.5.0 - you can download it from
www.systemhound.com or using the download button at the top of this site, or using the direct links provided in the readme.txt that came with your licence. Install over your current version, and that should fix the issue. As a test, you can re-install a client to a machine which did not previously report - remember to uncheck the box on the Install Wizard which says 'do not install if already installed' - and it should report back within a minute.