title: Installer built with PackageMaker only sometimes shows destination select screen
body: <p>I have built a simple installer with PackageMaker 3.0.5.  It installs a package into /Applications and some support files into /Library.</p>
  
  <p>The distribution is set to easy install only, System volume only.  Allow custom location is disabled for all of the contents.  The app is set to allow downgrade and not allow relocation.</p>
  
  <p>The installer does install correctly, but sometimes when I run the installer it displays a 'Select a Destination' screen and has a 'Change Install Location...' button, and sometimes it skips straight through to the 'Installation Type' screen.</p>
  
  <p>I would prefer the second behaviour, but could live with either.  My concern is the unexplained change in behaviour betweens runs.  Does anyone know what causes this, and how to stop it?</p>