Hi!
I just conquered a city while researching magic as well - perhaps the two events (next magic & city) bit themselves? System crashed straight to desktop on a big PC using Windoze 7 Pro 32bit.
debug.err: http://filebin.ca/qwxnmm/debug.err
Crash ZIP file: http://filebin.ca/guunrs/Elemental1_07-2010-09-03T21-02-31-584.zip
Ciao,
Klaus