One of my clients just put up an "Under Construction" page for their web site (hosted by Yahoo). Everyone outside their network can see it just fine. However, nobody can see that page from within my client's network. They see the "file index", which shows the file structure for their web site. This happens on every computer on their network. Doesn't matter if they're using Firefox or IE 6. Done everything I know of to clear this up including clearing out cookies, history & temp files from their PC's and flushing the ARP cache on their SonicWall Firewall.