According to Dylan Avery at his blog:

'Louder Than Words LLC will no longer be able to participate in the upcoming 9/11 Accountability Conference in Arizona on February 23rd - 25th, due to the involvement of Eric D. Williams who has authored a book promoting Holocaust denial, entitled "The Puzzle Of Auschwitz."'

Dylan has more at the Loose Change Forums:

"Eric is still attached to the conference. And apparently Kevin Barret has made some off-color remarks concerning the Holocaust as well. It's a very unfortunate situation for all involved."

This confirms what New Times blogger Stephen Lemons reported when he covered local ACLU honcho Alessandra Soler Meetze's withdrawal:

"PS: Meetze also let me in on the fact that recent e-mails from Knudson to her were cc’d to none other than Holocaust denier Eric Williams, who is supposedly no longer a part of the Chandler 9/11 conference."