If you are using Snow Leopard, you may have noticed that double-clicking on the title bar of a Vectorworks Palette may not window shade the palette. This is due to a change in the default behavior of the OS.
This only seemed to occur on machines that had OSX 10.6 installed fresh, not on machines that were upgraded from another OS version.
To correct this, go to the Apple Menu > System Preferences > Appearance and check the box for "Minimize when double-clicking a window title bar".
This will correct the issue.
Edited by JimW