From the Andrew Balis article:
> Set Up FCP Interface. Choose Window > Arrange > Multiple Edits. This re-
> arranges the windows, and opens up a couple more. If this window
> arrangement does not appear in the menu, it is because your screen
> resolution must be set to a horizontal resolution of 1280 or greater. If you
> want to change the resolution, quit FCP and go to your System Preferences
> (from the Apple menu). From there, choose Displays, then a resolution and
> then re-launch FCP.
I don't think dual monitors behaves as one wide one. That could be your issue -- your primary monitor isn't wide enough.