Those articles are quite old. the fist two are from the time we initially found the trailers, and we know that at that time we would find "WMD's" everyday, and later find out it was bogus. However I will concede that we can't be sure they were not used for making biological weapons. Here's a more recent article where David Kay sounds pretty convinced that they were not.

"And Vice President Dick Cheney cited discovery of two semi-trailers in Iraq as "conclusive evidence" that Iraq "did, in fact, have programs for weapons of mass destruction."
Here's David Kay on that canard: "When you look at those two trailers, while they had capabilities in many areas, their actual intended use was not for the production of biological weapons."

http://worldnetdaily.com/news/article.asp?ARTICLE_ID=36854

Dueling Duratecs '95 SE V6 MTX 0 Mods '04 Mazda6 S Wagon '03 Kawasaki Z1000 But thus do I counsel you, my friends: distrust all in whom the impulse to punish is powerful! Friedrich Nietzsche