The new Zippo BLU lighter should have beeen released in 2005. "Marlboro" was the first to order the new butane gas lighter, but there were some major problems with the inserts. Because of that the Zippo BLU lighters were backordered to be remanufactured. In fall 2006 the lighter was presented in Franfurt and some dealers in Germany were the first to get the lighter. Officially the lighter was available from Sept. 2007 after its second presentation on Frankfurt's "Herbstmesse". All Zippo BLU lighters were equipped with new inserts, the older lighters produced in 2005, too. This may be an explanation for the delayed release. In April 2007 the first "Marlboro" BLU-lighters were seen on ebay - they had the 2005 bottom but new inserts (just as mine).
(Excerpt from "Zippo BLU Praxis- und Erfahrungsbericht" by www.zippo-fan.net)