On Windows and Mac OS X, the keyboard shortcut to open or close the Navigator panel (Ctrl+Shift+0) may not work as expected.
Change the keyboard option in the operating system so that keyboard shortcuts can be used as standard function keys, not OS functions.
By default, Mac OS X 10.6 maps the function keys to OS functions. However, you can set a preference for them to be used as standard function keys, or to use the fn key with the function keys.
In Windows 7 and Vista, Ctrl+Shift+0 is assigned an operating system function. See this Microsoft support document for more information.