Situation: I'm plugging along, enjoying my game. I make it like 3-400 turns in and finally need a break. I save the game and come back to it at a later date and notice that ALL but the most recent techs in the tech tree have disappeared. I appear to still have the benefits of the skills, but the skills no longer show up as highlighted in a way leading one to believe that hey have been researched. I have no idea what I researched and what I have not researched that far in. This is also a custom race, so that might be an issue. Anyone experience anything like it?