JetBoil is voluntarily recalling some of their stoves with a "B" type valve. These stoves were shipped to U.S. retailers from July 10 to Sept. 9, 2008, and have been sold since July 10, 2008. All the information is here: JetBoil Recall Notice. Gotta love corporate responsibility.
Owners with questions should contact JetBoil at 888-611-9905.