You don't have any named saves? Even if they are too old to revert back to, you can at least test if they will load.
Can you start a new game, save it (using a named save, so as not to overwrite any quicksaves), and load it again?
Check if there are files called debug.lst or error.txt in the 'Beyond Divinity' folder.
Windows has been known to decide game files have become corrupt after a crash, even if the game was not involved, and 'fix' the perceived problem. One person had Windows delete all of the inv.b2 files in their Divine Divinity saves when another program crashed 5 minutes after exiting that game (fortunately it is a zero byte file, so was easy to replace). Another had a crash a few minutes after exiting Beyond Divinity, and Windows deleted that same file from the ..\main\startup folder, so it caused a crash starting the game, rather than just when loading specific saves (so not the problem in this case).
In Windows Explorer, browse to the '..\Beyond Divinity\savegames' folder, and check the number of files in the save folders. There should be 22-23 files in a save before entering the BF that act, and 28-30 afterwards.
Depending on the file, missing files might be replaceable with corresponding ones from the next most recent working save (if available); normally that could cause problems, but since you are at the end of the game there is less that could be messed up by mixing files from different saves.
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 folders for each user, and then map that folder to the game's savegame folder (so it will just see the saves for the relevant user).
If a new game crashes, as well, try deleting the files within the dynamic folders (not the folders themselves, though);
'..\Beyond Divinity\Acts\Act1\Dynamic', '..\Beyond Divinity\Acts\Act2\Dynamic', etc (also possibly mapped to the user folder path in Vista/7).
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 those folders, deleting the files should fix the problem.
FYI, below is a list of the files which must/may be in the save folder. The files with an extension of .1 or .x1 are added to the folder after entering the battlefield for a particular act for the first time.
automapgen.000 (after BF, may or may not be present)
dollinfo.000 (may or may not be present)
If all else fails I still have my saves from my first playthrough of the disk version, and could give you a save from before stepping through the final rift to Rivellon (with an archer hero).
Check your messages (click 'My Stuff' in the top menu bar, then 'Messages').