And this is tarbat's advice:
For any program that continually updates files in its own installation folder, I always recommend NOT using the default installation folder. I'd recommend a new folder called something like C:\Programs, and install Radarbox in that folder - ie C:\Programs\Airnav Systems\AirNav RadarBox 2009
Then make sure to set an exception for that folder in your anti-virus software.
This then avoid any complications with Vista's Virtual Store.
Just my opinion, but I've used this for many programs that update their own files.