Maybe a corrupt file in the dynamic folder got carried over from a previous game? That happened to a couple people (one person restarted with a different character, and found quest items missing if they had gotten them with their first character, for example).
To be safe you could delete all of the files in the dynamic folder ('..\Divine Divinity\Run\Dynamic' in the disk version '..\Divine Divinity\Dynamic' in the download versions) before beginning a new game.
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. The files will be re-created as required the next time you start Divinity.
Under Vista/7, depending on how the user accounts are set up, if you install the game to the default Program Files path, Windows can create separate savegame and dynamic folders for each user, and then map those folders to the game's folder (so it will just see the saves for the relevant user).
C:\Users\ %account name% \AppData\Local\VirtualStore\Program Files\Divine Divinity\[Run\]dynamic
