Inconstant Aliens

[Alafin]

I am fairly new to the game (just got it for Christmas). And have been loving it ever since. However, when I play the Extended Original Game and choose 7 civs., the alien civ invariably gets switched over at some point to the background human civ. I know this because from time to time I enjoy cheating to get a good look at the world (and by toggling, Centaurus as well). I know, I know...but I enjoy the graphics way too much not to. Can anyone explain to me what is going on and how to fix it? I have the Civ II ToT version of the game.

Thanking you in advance,

Alafin (Nigerian for king/emperor) Siyanbola