1. I recommend you update the server NIC drivers and NIC firmware to the latest version recommended by your server manufacturer. For example, for a Dell server you would download the latest System Update Utility (SUU), burn it to double-layer DVD,
and then run it on your server to apply firmware/driver updates/etc.
2. If updating the server NIC firmware/drivers does not solve the issue I recommend you disable TCP offload (and potentialy other advanced) features on your network adapter and see if the issue is resolved. Please see this article for more information:
Information about the TCP Chimney Offload, Receive Side Scaling, and Network Direct Memory Access features in Windows Server 2008
Microsoft is conducting an online survey to understand your opinion of the Technet Web site. If you choose to participate, the online survey will be presented to you when you leave the Technet Web site.