Regardless of what I do, upon the game proceeding to the following turn, the game will CTD without any windows error.

http://dl.dropbox.com/u/8970398/Elemental0_806-2010-07-11T21-49-53-470.zip

http://dl.dropbox.com/u/8970398/Elemental0_806-2010-07-11T21-45-20-356.zip

http://dl.dropbox.com/u/8970398/Elemental0_806-2010-07-11T21-42-50-961.zip

http://dl.dropbox.com/u/8970398/Elemental0_806-2010-07-11T21-40-59-442.zip

I included the four most recent logs, although they all end with a trading unit as the last log.  This may be similar to Publius of NV's CTD report, which also ends with a unit trade.