Have you tried building the AC client yourself? It might be the possibility of your openAL being either too new/old, than what was used in building it. That, or you're trying to run 32bit AC with 64bit libs. (just guessin')
Edit: i get 0 points for reading comprehension. :< I still suggest you try build AC yourself, tho.
Edit: i get 0 points for reading comprehension. :< I still suggest you try build AC yourself, tho.