I had to install recently a couple of HP Proliant BL460c G7 with FlexFrabric Embedded Ethernet adapter (dual port 10G), but these nics are not recognized by the ESXi 4.1 Update 1 installer CD. Here you can see only the additional dual port nic (HP nc283m) is recognized:

Instead of configuring the management network in the 1G nics and use the PowerCLI procedure, I used this time another method.

First of all, find on the VMware support site the right ISO containing the additional drivers and download it. Then, mount the iso using iLO on burn it and insert it in the cd tray.

Then, enable from More >