What to do when your external monitor pans around what should be its native resolution (ATI)
On my Toshiba Laptop, I had a weird problem this morning. My usual external monitor, a very bright Sony 1280 x 1024 LCD, did display at 1024 x 768 or so, but allowed me to pan around to see the entire 1280 x 1024 desktop. How to get it right? I apparently have an ATI Radeon Xpress 200M card in it. I tried to change the resolution, but all in vain, the display settings already reported the 1280 x 1024 resolution.
The trick turned out to be to right click on the desktop, select Properties->Settings->Advanced, and go to this tab:
Uncheck the "Preserve wide aspect ratio.." box (which was checked) and then click "Apply" You need to click "Apply" or you cannot make any changes to the monitor at the left.
Once you'ce clicked apply you can click at the "Monitor" text.
In the dialog that pops up, adjust the maximum resolution to in my case 1280 x 1024. It seems this setting applies to what you might call the physical size of your display, while the standard resoltion controls applies to a virtual size. As I am doing screen captures now, I notice that the settings is now 2560 x 1024 !
I did not set that, go figure... Anyways, tweaking the settings here got my display finally back to normal.