When using Adobe Photoshop CS4 in a dual-monitor environment, why is it that a secondary monitor's color becomes abnormal?

In a dual-monitor environment, color management is only correct on the primary monitor when OpenGL Drawing is enabled. (This problem does not occur unless the graphics board supports OpenGL) Under [Preference] in the [Photoshop] menu of Photoshop CS4, please choose [Performance], deselect the [OpenGL Drawing] check mark in "GPU Setting", and reboot Photoshop. Please note however, if OpenGL Drawing is deselcted, it will not be possible to use the functions(animation zoom and canvas rotation etc.) enhanced by the GPU.