you should empty the override folder. Sometimes if the game is loading an area and somehow you stop it (suddenly turning off the computer or something)a "broken" file is stored in that folder, so the game will try to read it the next time you go into the affected area and will crash again.
Try it out and tell us if it works.
Remember, if you have the Bonus CD or self-made items, save them up so that you can reinstall them later.
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"Let my spells do the dirty work" Ertai, High Sorceror of the Holy Flame