Just speculation, but with 7264 we now have a "new animal" that will not accept RC keys. COULD IT BE that the keys it will accept are those for RTM? If so, upgrading from 7260 (and previous RC builds) could verify that RC can upgrade to RTM. My 7260 upgraded fine to 7264 although I had the choice of re-arming or "hacking" the boot key files to accept RC. If M$ is getting close to RTM, maybe 7264 just proves the ability to upgrade from RC. I don't intent to go that path but many may choose to do so. THOUGHTS??????