Multiple Monitors

Config: iMac + OSX 10.6.8 (with all the updates), 1 additional monitor (Cintiq 21UX). In System Preferences/Displays/Arrangement, I place the second display to the left of the iMac, and drag the Application Bar to it. This works as expected when both monitors are on. But when I turn off the second monitor, the application bar does not go back to the iMac (which is now the only display left). "Discover displays" etc. does not help. The idea is to only use the second monitor for Photoshop - when I do, I want it to be the main monitor. When I turn it off, I want to revert to a baseline iMac.

Thanks in advance for your help.

From what I understand , the multiple displays are not based on whether the display is powered on or not, but whether the Mac sees it as a connected device. You may need to either remove power from the monitor completely, or disconnect the video cable from the back of the iMac. Even with power turned off to the display, there's enough trickle current passing through the cable for the Mac to recognize it's there.