Opening new windows with GNOME File Manager

[msh <mmaa worldnet att net>]

I am using the default GNOME installation that comes with RedHat 6.0.
In the GNOME Help Browser in Chapter 7  under the section: Moving Around
the GNOME file Manager, the following tip is given:

    "TIP: You can open a secondary window by using your middle mouse
button on any directory.  Press the
    middle mouse button (or both left and right mouse buttons if you
have emulation) on a directory in the
    main window and a new window will open showing the contents of the
directory you clicked on."

I've tried this and can't get it to work.  I've also tried clicking in
other areas (like the directory tree view) and
changing the view in the main window from Icons to Brief to Detailed and
nothing seems to work,

What am I doing wrong?  everything else seems to work fine.