VMWare - ESXi 4
Windows Server 2008 sp2 (not R2)
Used VConverter (current version), stopped Exchange services prior to P2V, left config default.
Verified NIC config. Ghost NIC in system, but 2008 removing config from Ghost when config on new (virtual) NIC takes over same config.
This turned out to be quite the beast, and it's not even fully vanquished.
I did not ever figure out what was going on with the first P2V process, it was just bad in some way. All the configuration matched exactly with the physical (functioning) exchange server, and there was just no communication over what appeared to be valid connections.
Not having enough time to continue diagnosing, we ran a second P2V on a subsequent evening, which also didn't work, but this time it was just that the new VM never loaded the OS. Third try appeared to be similar, but turned out to actually be a good copy. At first it appeared to have the not loading issue of try #2 and so I backed out of that too. However, it turned out the issue was a compatibility problem between the RDP console and the vSphere machine viewer resulting in nothing showing in the viewer window when viewed over an RDP connection.
We used this good copy to test the sending and verified it was all working OK. Some Outlook clients needed to have the Cache disabled and then reenabled to "see" the new server in test. It seems the Cache keeps some record besides the domain name and IP address and so if the client is running during the migration, it can get hung up looking in the wrong place for the Exchange server once it comes back online.
So, we've figured out that and I'll be giving it another try tonight, eschewing the RDP console to ensure maximal chance of success.
Regarding the initial issue, Microsoft and our Consultants both recommended simply re-
P2Ving as there was no reason they were aware of that the original issue should have occurred.