Yesterday I installed the latest security updates for my ibook via software update. I'm not sure if this is related to my problem, but I thought I might as well mention it. A few hours after installing the updates, I turned on my computer. Everything was running fine, however as I was listening to music and surfing the internet, my screen turned black. I checked the contrast and it was all the way up. The screen then turned completely off. Upon restarting the computer, my screen got to the loading page with the apple icon and the loading circle, and then turned black and flickered every so often with a screen of vertical multi-colored bars. I held down the power button to turn the screen off, and the flickering increased, before becoming completely covered by the multi-colored bars and then shutting off. This morning I tried again and my computer actually booted up. However, after a few seconds the screen went black, paused for a few seconds, then went completely red, then green, then blue, then three shades of gray, and finally black again. It repeated this cycle twice before the screen turned itself off. Is this a virus, or hardware/software malfunctioning. I've had my ibook for two years and was wondering what everyone's suggestions are for what I should do to fix this problem, if it is possible. Thanks in advance!