It probably doesn't help you now, but I had this issue too. It turned out that ESX chose one of my unused network interfaces as the new SC interface after the upgrade. I just moved the cable to that port (I had two free ports and just picked one) and voila, the SC started working again. The actual TCP/IP stack and its settings never changed, just the SC's physical interface assignment. vmkpcidivy evidently went away with 3.0 by the way, and I didn't know how to check hardware allocation at the console command line until this posting. Thanks.