Geforce 3 for use in a G4... Help!

[CiNoRi]

Recently I had a friend Flash the bios of a GeForce 3 Vid card for use on my G4 450... It seems to work except for when I type, a web page loads, or when clicking the mouse...ect....There is a slight flicker on screen.
Has anyone ever done this or had experiences of it?

Thanks!!
-Erica:???: