Sounds easy enough, right?
We have one organization that loses their internet connection at least one time a week, if not more. The quick fix is to change the WAN IP address in their router by one number (e.g. xxx.xxx.xxx.242 to xxx.xxx.xxx.243) and that gets their internet connection restored temporarily.
We've tried changing routers and that doesn't help. None of the computers have anything goofy switched on in Windows firewall and they are all running Windows XP sp2 w/ Firewall turned on. They all have virus protection and are up to date. They all have been cleaned of spyware. We're spinning our wheels trying to figure out why this one organization is having the problem and no one else is. We've tried plugging their router into a different port on the main switch but that doesn't make a difference. We've done everything we can think of except for unplugging one computer from the network at a time and leaving it unplugged to see if the problem still exists without it being in the loop. (That's not really a viable solution either, because someone obviously needs to work on the computer and wouldn't be able to with it down.) When they lose the internet connection, they can still see each other and the router, they just can't get outside of the main gateway to hit the internet.
Everyone we talk to has no idea either. Any ideas?!?