I am working (and testing) in a build somewhat more enhanced than CI 1.2 (it's 1.5) so that'll be no good to you. I have started testing BI vanilla 1.6 though.

I attach the link to my saved game. Please use all vanilla (BI 1.6) files with the exception of the EDB which should only be altered by placing a semi-colon before the sassannid-peasant recruitment line for the city-level govt. bldg.

http://www.megaupload.com/?d=RBZGWS3M

This is me taking the Huns down to attack Artaxarta. It CTDs even with a garrison in my tests - perhaps you can spot what we are doing differently?

Will report back on your saved game shortly.