Update Vulnerability DB fails

I had to fall back to a backup of our Desktop Central server, version 80001 (July 2012). I applied successive service packs and releases to bring it back up to version 80262, and I reapplied the new license file so that it's registered through July 2014. Things are almost back to normal, but when I try to manually "Update Vulnerability DB" the process runs, getting to the point of downloading patch SQLs (successfully) and then syncing security updates (fails after a couple of minutes).
I tried following the procedures for manually updating the server on a closed network (https://localhost:8383/help/configuring_desktop_central/patch_management_for_closed_network.html), setting the proxy to "no direct connection" and running the update procedure from another connected workstation. When I run "Update Vulnerability DB" on the serve (after copying the updatedb over to the server's \conf\CRSData ) the update doesn't fail, but there are no new updates showing up later than July 2012 -- even though I've manually scanned some of our Win 7 workstations.
Is there something wrong with the manual procedure in the referenced document? Is there something I need to do on our server to force the vulnerability DB to update?
Thanks for your assistance.