Same thing happened to me and i was so looking forward to SMAC after playing civ3 for a month!
It must be something to do with windows ME but im using it too.
Ive just been fiddling around with i for awhile but still no luck.i suppose i could start a new game of civ3 but i just cant be bothered aat the moment for all the tedios gameplay.
The tech support were no help either.
Lefty did you have to install anything else except from the pach to make it play?