Sometimes I hate computers.  They can be so irrational.

After reinstalling the Galciv II game and all expansions I started a metaverse game.   I played for ages and ages and no problems. 

Came back after a weeks abscence and guess what?  The planets just went missing from the main map.  And they won't come back.

The icons are still there, they have replaced the planets.  And the ships orbit around the invisible planets.

It is not a case of savegame corruption, since new games have the same problem.