Back in May I reported on problems with ESXi 4.1 and the Emulex OneConnect CNA that is built into HP's G7 blade servers.
If you now try to install ESXi 5.0 on such a hardware you will have a strong déjà vu: The be2net driver that is available right now for ESXi 5.0 is not really functioning due to "VLAN tagging issues". HP has published an advisory on this stating that an updated driver (that should fix these issues) is "currently in the certification process" and will be made available in "Q4 2011".
Okay, I won't update our production hosts to ESXi 5.0 that soon anyway, but I just wanted to install it on some spare blades for testing and evaluation. Too bad ... waiting for a fix again ...
HP has now updated the advisory and published an updated firmware that fixes the VLAN handling problems with ESXi 5.0 if it is used together with the be2net driver 4.0.355.1.
Be sure that you read the release notes of the firmware! It looks like it is an emergency/workaround release that leaves many issues unresolved. A firmware version that you can really trust for production will probably be available mid-November.
In the meantime it looks like all problems have been fixed with newer firmware and driver versions. Please refer to this newer post of mine!