If you change the default gateway, or switch between DHCP and a static IP address, after installing the Windows Server 2003 Scalable Networking Pack on Windows Server 2003 R2, you receive a STOP 0x000000D1 BSOD (Blue Screen Of Death) similar to:

STOP 0x000000D1(parameter1, parameter2, parameter3, parameter4)
DRIVER_IRQL_NOT_LESS_OR_EQUAL

This behavior occurs when your computer is using a TCP Offload enabled network adapter and the new route is not fully initialized when Windows Server 2003 R2 checks to determine whether a reconnection to any existing connection can be made over the same path.

NOTE: Microsoft is researching this problem.