Service Pack 3 causes DCOM to remember connection information. If your computer has multiple NICs, and one becomes disconnected, DCOM will try to connect on that adapter, even if it is unplugged.
When a connection request is received, DCOM times out the connection after 3 unsuccessful pings. Since these pings are separated by 2 minutes, you experience a 6 minute delay before the other NIC is connected.
NOTE: Any program that uses DCOM is affected by this behavior.