Here are two recent KB articles for Windows Server 2003 and 2008:

http://support.microsoft.com/?kbid=944135
The recvfrom function stops responding when you use the sendto function in the IPv6 raw socket to send an ICMP packet and then use the recvfrom function to receive ICMP responses on a Windows Server 2003-based computer
1/24/2008
Windows Svr Ent 2003 EN

http://support.microsoft.com/?kbid=947042
The IPv6 connection protocol is not negotiated correctly when you use the Netsh utility to configure the Routing and Remote Access service on a Windows Server 2008-based computer
1/21/2008
Windows Svr 2008 Ent AL