This sounds likely to be the copy protection system.
If Space Colony is on a CD. Then ensure you are running version 1.1 (shown on the main menu), if you are not, download the patch:
http://www.fireflyworlds.com/index.php?option=com_content&task=view&id=164&Itemid=247
Also, you may have updated a downloadable version of the game, using a patch for the CD version. If so, you should uninstall the game and reinstall it but do not apply the patch.
