I have the same problem as other post on this topic, I have tried another monitor with the same results. It does not do it when res is set to 800 x 600 at either 16 or 32 bits. As soon as you go above this resolution it starts flashing at about 5 second rate. It seems to do it pretty well from cold, well about 3-4 minutes, could it be a heatsink problem on cpu or graphics chip or is this a known Dell Dimension 3000 problem. I am trying to lay my hands on a pci graphics card to eliminate that possibility.