I have an iMac that looks the same as the new ones, just white. It is PowerPc G5 with 1.5 GB of RAM (1GB, 512MB). It oils getting lines that are 1 pixel thick. I have a Green 255 line that popped up, and then, about a week or so later, a red 255, and they are bout 25 pixels apart. These lines are vertical. I expect a blue 255 soon and I want to know what how to solve the problem, if it is a display or a computer problem, and if it can be solved reasonably by your average guy for a cheap price. Please help, thanks!