One thing to watch out for with many of the Belgian beers is their age. Culturing is only really succesful with a reasonably fresh bottle, and since Belgian beers do not exactly fly out the door of most bottle shops you will generally find that they aren't too fresh (I recently purchased a bottle of Cassis Lambic that was over three years in the bottle - bloody marvelous drop, but useless for yeast culturing).
Cheers,
Pete
:chug: