Wow, talk about obscure. It seems one cause of the activation problems some people have had is a seemingly innocuous registry value placed there by another program prior to installing FSX. So far we've determined that Iomega backup software is one culprit but there may be others. Apparently the software is "supposed" to set a valid value that the activation component looks at but instead it just writes a '0'. Essentially what happens is the activation component says. "What the %$!?", and bails out. Some people have had success by un-installing the backup software and then trying to activate. I'm looking into whether we can post a manual fix for those of you who feel comfortable editing your registry. Stay tuned.