yup, that's what I meant by drivers giving windows limitations on monitors, it tells the operating system what the monitors limits are so it does not go outside those limits.
I have hunted about a bit and not found a specific driver for it. So I suggest you force windows to change the driver its using to "Digital Flat Panel 1280 x 1024"
To do this your going to want to start by making a restore point. Go to start, all programs, accessories, system tools, system restore, make a new restore point and name it whatever you like.
Next go to start, right click computer, choose manage, then choose device manager, hit the plus next to monitor, right click the listed,"Generic Non PnP Monitor" and choose update driver....
Next you will need to put the dot in "Install from a list of specific location. Then click next. put the dot in Don't Search, I will choose a driver to install, then click next again.
Take the check out of "Show Compatible" and it should give you a list of drivers, in the right pane scroll up and choose the Digital Flat Panel 1280 x 1024, , if it warns its not the right one, say ok anyway and then finish out the setup.
once done reboot and see what you get. This should force the monitor to now be limited as you needed.
If you need to revert back, just go back into device manager and remove the driver by right click, and choose uninstall, reboot and windows will redetect and put back in the Generic.