Yes, that's some problem you will always have, if the recording version is different than yours. As well you will only see players with your version of the game on the server. Everybody with a different version is simply not displayed. Those two are the main reasons, why it is usually kind of necessary to have the latest version running. Not really because of new features or bug fixes, but for having the same version as everyone else.
I was thinking: How about an ufo2000-saturday, or something like that? I was thinking about the whole saturday, 0 AM +12 to 24:00 PM -12. Advertisement: If it's saturday, connect to the server! If everybody takes at least one hour waiting there, it's likely there will be at least one other player at any given time on that day, giving everybody the chance, to play xcom against a real opponent. It sure would need some advertising, but maybe, if promoted enough, the game would get rolling again... I believe, the infrastructure is available.