Go into 'Edit'.....then 'preferences'......then 'QuickTime Preferences'
Then 'File Types'.....
Select the types you want QuickTime to handle......
In this case....you go into the 'Video' section........check the little 'QuickTime Movies' box......Brian's recent ones are .mov so they fall under that.
Make sure the 'Notify me if other applications modify these associations.' box is selected...cause when you open Real Player or Windows Media Player or w/e....they will try to steal the file associations back. There should be an option in Real and WindowsMP that you can deselect so they STOP doing this.