ESXI 5.0 does not support Dell PowerEdge R320?

I've bought vCenter Server 5 Essentials; and I need it installed on a server Dell PowerEdge R320; but during the installation proccess I get the error "No ethernet cards found, press enter to reboot", and can't install it!! same thing with ESXi 5.0 and ESXi 5.0 U1.

According to the compatibility list this server is compatible.

http://www.vmware.com/resources/compatibility/detail.php?deviceCategory=server&productid=19269&deviceCategory=server&keyword=r320&page=1&display_interval=10&sortColumn=Partner&sortOrder=Asc

Even in the Ethernet I/O Compatibility list, the R320 have 2x Broadcom Gigabit Ethernet BCM5720.

What can I do?

Regards.