This NIC doesn’t have the same complication as the HP NC373i but there’s still a gotchya to watch out for. Do not use the HP Network Configuration utility to assign a VLAN tag to the NC326M, even for a temporary test. Even if you remove the VLAN tag from the NIC, there’s still something left behind by HP’s utility.
I found that if configure a virtual switch on a clean machine with the NC373M then there were no problems at all – as long as the HP Ethernet virtual connect is wired and configured correctly.