Auto-adjust is a feature for VGA connections. Because VGA is an analog signal, the image constraints and some of the signal frequencies vary slightly from source to source. DVI, being a digital signal, does not have these inconsistencies (or at least, can define them for the display device), and thusly, does not require use of the auto-adjust feature (it essentially happens transparently).
Anyway, mjserv, try looking in the display's built-in configuration menus for display mode settings like "letterbox" or something that might cause the display to shrink the picture. Being a DVI signal, it's unlikely (although not impossible) that Windows 7 is to blame. You can also try resetting the display's settings through its configuration.
Has this display been known to work correctly at 1680x1050 on any other computers/operating systems?
Also, am I the only one who finds it extremely confusing that the display's model number contains the string "1080P" when it doesn't display at a resolution (or even an aspect ratio) anything close to 1080p?
--- Mr. DOS