Shift clicking and selecting all the units in Esnoon and then attacking Lord Markinn from inside the city causes the game to crash. I tried going outside the city first then attacking and it didn't crash. Another thing I noticed was how when i selected all the units inside the city and attacked him, they go 1 by 1 instead of acting as an army. He kills the first Nomad then crashes on his second victim.
DXDiag: http://pastebin.com/mp6fDtYb
Saved Game: http://dl.dropbox.com/u/8088480/AttackfromInsideCityCrash.EleSav
Debug file: http://dl.dropbox.com/u/8088480/Elemental0_802-2010-06-17T01-37-53-750.zip
Note: For some reason this crash produces a debug zip file everytime.