Difficulty installing IWDification in BG2:EE

Hello all,

I've downloaded IWDification Beta 3 for my BG2:EE steam installation. I've created the hardlink for dialog.tlk in the game directory (i.e. steam/steamapps/common/

However, when I attempt to install either the Arcane or the Divine Spell packs, I get the following error:

ERROR: BIFF [./DATA/EE.BIF] cannot be loaded: Invalid_argument("String.create")

Stopping installation because of error.

(repeats this error four more times)

Anybody know what's going on and how to fix it?