[Usability] checkbox or popup menu?

[Jacob Kolding <jacob omnia dk>]

In my app (http://discomatic.sf.net)
I have a treeview of folders and I'm currently incorperating
the ability to view the individual files of each forlder.
But I want the user the be able to change whether files are 
shown or not.

My question is then, should I use a checkbox that set the option
globally for all folders (Like xcdroast does) 
or add a right click popup menu with a check menuitem for each folder?

/Jacob Kolding