Did you try deleting all of the files in the '..\Divine Divinity\Run\Dynamic' folder?
This folder is used as a cache for the game. Files are created / copied there from the save game folder when you load, and written / copied from that folder when you save a game. It is rare for a file to become corrupt (though a system crash and hard reboot ups the odds), but that could account for your existing saves crashing during the load process. Had you not already reinstalled the game, deleting the files in the dynamic folder would have been my first suggestion (it can not do any harm, at least, since the files get re-created as required the next time the game is started).
It is also possible that after rebooting, Windows decided recently accessed files were corrupt and 'fixed' one or more of the game files (though in that case, I'd expect new games to also be effected). One person had a system crash 5 minutes after exiting the game, and during the reboot Windows deleted the inv.b2 files from all their recent saves. Fortunately this is a zero byte file (perhaps why Windows decided they were corrupt) so it was easy to fix.
