Problem with 8400GS (Vanilla 10.6)

[JonKenobi]

Hi guys! Sorry if this is in the wrong spot, so mod, feel free to move it as necessary, I'm still new to the boards.

 

I've been having a little problem lately. I installed a vanilla 10.6 on my system, at the time of installation these were my specs:

 

Gigabyte G31M-ES2L mobo

E7500 Core 2 Duo 2.93GHz

2gb of 667 DDR2

Radeon x1550 512mb (x7143)

 

Since the installation i upgraded the RAM to 4gb of 800Mhz DDR2, with no issues. But then, I decided to upgrade my video card because the infamous x1550's lack of QE/CI.

 

i purchased a ASUS EN8400GS 512mb Device id:0x06e4, after installing it and booting up, OSX recognized it immediately, I booted up with all resolutions available and QE/CI enabled by default. This is all without installing any new kexts/injectors or modifying any EFI strings.

 

The problem I'm having is that ever since the new video card was put in, OSX has become extremely unstable, especially when using apps that require QE/CI like iDVD or even iTunes. Also, when I turn on or reboot the computer, the login screen doesn't come up, I just get a black screen with a mouse cursor, but if i tap the power button, the screen flickers and my login screen comes up.

 

Have any of you encountered a similar situation? Any help would be greatly appreciated. Hopefully without having to reinstall all over.