Are you still playing the disk version of the game? I don't know if anyone had tried the item editor with the download version of the game.

Do you have any equipment in your inventory? In a new game you may have auto-equipped something you picked up intending to edit.

Are you opening the items.000 file in the save you are trying to edit?
Each save is a separate subfolder in the '..\Divine Divinity\Run\savegames' folder.
Under Vista, depending on how the user accounts are set up, if you install the game to the default Program Files path, Vista 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).
C:\Users\ %account name% \AppData\Local\VirtualStore\Program Files\Divine Divinity\Run\savegames


It is possible to edit your character's sight range directly.

Some more hex offsets... (see Teleporting Anywhere, via hex editor as a reference)