I have a mother board with the following integrated graphics:
geforce 6150se nforce 430
I first attached SyncMaster T260HD that has a maximum resolution of 1920x1200. On right-clicking (WinXP) display, I was getting a max resolution option of 1920x1080 in dialog box.
I installed monitor (Samsung T260HD driver). Still Windows XP Display dialog box showed max resolution of 1920x1080.
I right-clicked and chose nVidea control pannel. The nVidea Control Panel was showing 1920x1200 (native) resolution. I chose it and it worked. Now my Windows XP display is also showing 1920x1200 resolution.
I am not sure, but I think you should look for your monitor driver at Samsung support site. If there is one, then install it, and reboot. Then go to nVidea Control Panel and see if the resolution is showing there.