I have a DC 2.0 2003 G5 with 8gb ram and ATI 9600 pro running 10.5.8 from ssd. Last year I bought a 6800 DDL Ultra that had seen alot of use, and it showed wavy vertical lines and caused a grinding halt before login in osx. Single user boot gave me a desktop but stil a bit different wavy artefacting. ASD 2.5.8 returned vram issues. I gave up and returned to the 9600 pro. Now, I bought a cheap 6800 DDL GT that was still in the box and in mint condition for cheap, and it too showed exactly the same symtoms, although a bit less artefacts in single user mode. What are the odds for this? Do I have an issue with the AGP port? Others with the same issue? I’m handy with the iron if it is needed.