Gigabyte Radeon 9000PRO with 2405FPW

Hi all,
I am having issue gettign the 2405FPW to work at 1920x1200 or any 1920 resolution with the DVI connector. it is able to run at 1920x1200 with the DVItoVGA connector. I think i am missing something here. i am using the Omega 6.5 Driver. I have also install the Dell monitor driver. When ever i select 1920x1200 the screen will go blank. so the max i can go to is 1680x1050 with the DVI connection but if i use the DVItoVGA connector i was able to get up to 1920x1200. so what is the problem here. i want to left the VGA connector on the monitor for other computer which doesnot have a DVI connection. Pls help me so i can use the DVI with the radeon9000PRO and VGA with another computer.