Try this and let me know how it goes.
Make sure to install the monitor driver as well. It makes a big difference 100%.
So far, I remembered that it worked on DG43NB.
Thank you for your reply. Actually, I tried both (driver and inf) but 1440 x 900 never showed up. I think there's some setting in bios migh cause this problem but I am not sure. It will really help if someone has the same board and have successful experience. Then, I can try the same set-up to see if it works.
Thanks for your help anyway.