I'd love to hear why a hydrogen generator needs a fermenter. Any chemists want to weigh in on this?

Again, the pre-media quote from Kay:

We have not yet been able to corroborate the existence of a mobile BW production effort. Investigation into the origin of and intended use for the two trailers found in northern Iraq in April has yielded a number of explanations, including hydrogen, missile propellant, and BW production, but technical limitations would prevent any of these processes from being ideally suited to these trailers.

That said, nothing we have discovered rules out their potential use in BW production.

You will not see that last sentence in any media quotation, but you will here. Note that he says the design of the trailers are not specifically suited for ANY of the possible uses. This is very odd for something designed to accomplish a specific purpose, but not odd at all for something that may have dual-use options.

As for them being used for hydrogen production, I've gone over this before. I've seen hydrogen production trailers for artillery use, including the ones built by Marconi, and these aren't hydrogen production trailers. If you can come up with a plausible reason why Iraq would completely reinvent the technology for simply filling balloons from a portable source, something that is available from a number of civilian and military vendors, let me know.