Error: Unable to obtain hardware information for the selected machine.

Here's an odd problem I've found in VMware vSphere 4.1 while trying to export a VM. When wizard for export was called, it runs a hardware inspection, and I couldn't get thru it because it was showing that error:

Error: Unable to obtain hardware information for the selected machine.

Like any respectable sysadmin, I googled the solution, but I could only find vConverter stand-alone issues regarding VMs registered as Windows 2008 R2 and software not being able to handle that, so a change to Vista 64 was needed. However, this was not the case.
Digging in the VM settings, I was able to find problem. It was in the NIC configuration. Somehow something changed it and left the distributed switch assigned, but not the port. I looked like this:

I'm still looking for the reason how it would happen, but it could be that specific port got deleted, or maybe vSphere is just messing with me. Anyway, keep your eyes open for this!