Can only open website once

I recently bought a new Acer desktop with Windows 7 Home Premium installed. I also upgraded my router to a Linksys E1000 (wired connection, not wireless), and am now experiencing an extremely strange internet problem.

I have a website I run, Sarak Apartments. When I boot up my computer I can log into the website in IE just fine, and I can FTP into just fine. However this only lasts for 2 to 3 minutes. After that everything with the website just stops working, I can't view it in IE (or Firefox, Opera, and Google Chrome), and I can't FTP in. I have to restart the computer to get it to work, and again it only lasts 2 minutes. This is 100% repeatable every time.

My roommate, who is also wired to the E1000 and is on XP, has no problems like this. This leads me to believe it is related to Windows 7. Here are the things I've tried with no luck

- Reset router/modem
- Restore router settings to their default (I didn't actually make any changes in the settings)
- Unplug the router and go straight from the modem to my computer. This eliminates the router as the source of the problem
- Safe mode

I'm completely out of ideas here and think it has to be related to Windows 7, since there are no problems with the website on other computers and no apparent problems with my internet connection.

Any ideas?

Thanks so much everyone

Thanks for the quick reply!

I turned off AVG - same error. I don't have any third party firewall programs, so I tried turning off Windows Firewall and have the same problems.