it could be the MTU issue. check this page for the details.

troubleshooting ie issues ... 2) This problem is caused also by an incompatible MTU networking setting. ... lower MTU as the default for all Internet communication. ...
     www.chicagotech.net/troubleshootingie.htm  

Don't send e-mail or reply to me except you need consulting services. Posting on MS newsgroup will benefit all readers and you may get more help.

Bob Lin, MS-MVP, MCSE & CNE
How to Setup Windows, Network, VPN & Remote Access on http://www.HowToNetworking.com
Networking, Internet, Routing, VPN Troubleshooting on http://www.ChicagoTech.net
This posting is provided "AS IS" with no warranties.

 I have a new computer hooked  up to ADSL via a router, I am constantly
 getting knocked offline. Never had this problem before with old computer and
 Windows 2000.  It happens often if I try to access video like at NBC.com etc.
 Is it a LAN card problem? router? computer? Can I slow down the transfer rate
 and if so would that help? I appreciate any help. Keith