PAXTER1,
Sounds like Garmin needs to buy you a MacBook Air:-)
It sounds like you may not be running with English as your primary language on your Mac. As it said on the download site, this BaseCamp beta will not run unless English is your primary language. If you really want to see the beta, you can go to System Preferences->Language & Text and make English your primary language, launch the BaseCamp beta and then change the language back to your normal settings. BaseCamp like most apps only cares about the language setting when it is launched.