The problem is caused by the version of the Monitors Control Panel. Installing v7.3.2 (or newer) of the Monitors Control Panel corrects this problem. You can find the correct version of the Monitors Control Panel on the Apple Multiple Scan Display Software Disk.
You do not need to go through the entire installation process to correct this problem. Simply drag the Monitors Control Panel from the Apple Multiple Scan Display Software Disk to your System folder.