You didn't by chance backup your saves to CD-R and restore them did you? If so, in Windows Explorer select the files in each save game folder, right click, select Properties, and clear the Read-only attribute (no checkmark).
If that wasn't it, try deleting the files in the dynamics folders;
'..\Beyond Divinity\Acts\Act1\Dynamic', '..\Beyond Divinity\Acts\Act2\Dynamic', etc.
These folders are used as a cache for the game. Files are created / copied there from the save game folder when you load, and written / copied to those folders when you save a game. The files will be re-created as required the next time you start Beyond Divinity. If there was a corrupt file in that folder, deleting the files should fix the problem.
Check the number of files in each save folder. There should be 22, 28 or 29 files per folder, based on a quick check of my own saves.