SAM March Definitions Update problem

Two readers (Pierre Talbot and Yvon Couture) have reported an identical problem with the March 97 Virus Definitions for SAM 4.x. Using SAM version 4.0.8 on a PCI-based Mac, SAM will not open. Instead, they get an error message that says: "The SAM Virus Definitions file is invalid." This did not happen with the February update. Interestingly, both readers are from Quebec - although I doubt that this is relevant to the problem (indeed, several U.S. readers have now confirmed this!; one reader found that reinstalling the SAM application and extension got things working).