Thanks again for your help,
The 1st link is related to vServer 5.1, not 5.0.
The interface is different in 5.0, or at least it does not display what that article describes.
The only logs that are available from the web client interface is through the "event Console", and that shows nothing that appears to relate to my issue.
The second link was more applicable to my circumstances.
Using the appliance interface that runs on port 5480, I was able to download the log bundle.
That bundle contains more than 450 files, so I'm not sure where to begin.
I searched that bundle's contents, but could not find any log with "virgo" in the name.
Given the low priority of this project, I think I'll simply try destroying this installation and starting from scratch, either trying again with the virtual appliance or with the Windows-based version of vSphere server 5.0.