i had downloaded the different RC versions onto my mac; all of them went into the ~/Downloads folder. the application bundles were named PixInsight.app, PixInsight 1.app, PixInsight 2.app, etc.
the updater won't run if there's a space in the filename. RC7 happened to be "PixInsight 4.app" and changing the space to an underscore fixed the problem.
probably somewhere there's a missing escape or set of quotes...
rob
