Sean - there was no distributed virtual switch involved.  This was a plain-vanilla in-place upgrade from ESX 3.5.  I suspect that the ESX 4 Service Console is no longer tied to NIC 0 on the host. For your customer I recommend upgrading to the latest ProCurve firmware release as I did.  The easiest way to do this via TFTP upload.  I blogged about the free Solarwinds TFTP client I used <a href="http://blogs.egroup.jasonmangone.com/?p=1469" rel="nofollow">here</a>.

Thanks for reading!