Keynote 1.0: "Computer does not have enough video random-access memory" Alert

Symptom

When you play a slideshow and then connect a second display to the computer while the Keynote application is open, an alert with this message appears:

"Your computer does not have enough video random-access memory (VRAM) to play the slideshow at the current screen resolution"

Solution

Quit the Keynote application before connecting a second display,

or

Download and install Mac OS X 10.2.4 or later. It is available from the Software Update pane of System Preferences, or from the Apple Software Downloads website (http://www.apple.com/swupdates/).