I have a Samsung SyncMaster 204b that I use as an external display for my Macbook Pro 17" running OS X 10.6.2. Normally, every thing works fine, but for some reason although the display is detected and displays the display control panel, I can not move my mouse or windows to it. In addition, the control panel appearance pane appears blank, an image is attached. I can't find mention of this anywhere on the internet, including apple forums.