Hi greyposter, antivirus warning from the router �Flashed upon the Screen� you must
have malware on your computer or you use the Check Point ZoneAlarm® Z100G
Secure Wireless Router.
2Wire devices can do this sort of thing at least for parental control stuff, i.e. got to a site on the routers blacklist and get a 'you are not allowed message', it is concievable that they're spotting some traffic patterns and intercepting the HTTP requests.
Screen shots, further investigation though seems wise