Help Needed About IGP

Hi;

I'm using an ECS mobo with AMD 780g chipset and o/b Ati HD3200 graphics.
I had an Ati x1650pro and wanted to try it; but when i try to use it; computer boots normally but in the Windows screen it crashes; there's weird blinking lines and dots, i can't see desktop.

I've updated BIOS
Updated chipset drivers
Changed my PSU to a FSP 600 Watt psu

Nothing...

It boots in safe mode with x1650 pro. Nothing seems wrong.
It normally boots with o/b HD3200; i can see x1650 Pro in Hardware list. When i checked it from Ati software it lists x1650 as "Disabled Device"

System:

ECS 780 GM-A Mobo
4 GB Kingston 800 MHZ RAM
AMD 5000 CPU
600 W PSU
Etc.