Ok, I've been able to replicate this a few times already. Anyways, I have the save file. Maybe it's from building that second city? Anyways, to get it to happen again, either use the pioneer from the city, or the sov (Asshat) , to go and found a new city right next to the gold mine and arcane temple. Then build everything you can. The save starts at turn 67 I believe. Once you get to turn 81, it doesn't go beyond that. You can still move the map around, select units, everything appears to work fine, but it never goes past turn 81. Ok, another 'Doh! moment. As I was typing this out, I started remembering something about auto-explore. I tried again, and turned the peasant I had off auto explore and was able to get beyond turn 81. Still, something should pop up to inform you why you can't actually end turn. I'm still including my files in case.

http://dl.dropbox.com/u/8949112/7-31/1.EleSav

http://dl.dropbox.com/u/8949112/7-31/debug.err