You can create folders in ClassView - right-click the project and select New Folder. You can then drag classes into the folder. Unfortunately you can't manage global functions in this way. An alternative is simply to remove the headers from the project. They aren't required to be part of the project in order to compile - dependency analysis will pick them up. Obviously you should not remove them from source control, if you're using IDE integrated source control.
Stability. What an interesting concept. -- Chris Maunder