Unable to get native Resolution of 20" LCD even after installing 10.7 ATI CCC for integrated ATI Radeon HD 4200.
First time I installed 10.2 from gigabyte utility CD and got 1600:900 resolution just for 2 days. After that I wa unable to detect it through ATI CCC or from Control panel, even there is no option for 1600:900 tried to detect it after reinstalling LCD drivers. Still no help.
The uninstalled ATI CCC and Installed 10.7 but got that native resolution only for a day.
Then finally reinstalled windows 7 and installed 10.7 straight away got resolution untill next boot.
Installed WinFast PX9400 GT(of a friend) installed drivers for it and able to get native resoltuion of 1600:900 even bigger than that through VGA andd remains constant on 16:9 rsolution for 1 and half week without any issues, as soon I removed PCI Express card angain back to 1280:1040.
So Again uninstalled 10.7 and installed 10.6 however still same.
More about :unable native resolution 1600 900 fromati radeon 4200
I recommend that you get a cheap discrete card to get your native resolution. The integrated graphics may be defective. Get something small if you don't need the extra processing power like the GT 220 since it performs very well not on games.