a few days ago i unplugged a USB cable from the back of my MacPro 1,1 and the screen turned all blue (like an overlay) and the machine crashed. Since then the computer has been running extremely slow it takes 15-20 minutes to start up (if not more) and once booted, every action is delayed as the computer is "thinking". I can type about three letters into a search box per minute as an example. The machine has moments of clarity where I can open a window or start launching a program, then to begins to pause again. The machine as of now is unusable. I have been able to get the process manager open and did not see anything unusual. So far I have reinstalled 10.6, done the usual disk utility things, reset the SMC, and reset the PRAM. All with no effect. I did notice that the screen flashes bright magenta on startup now... Any other suggestions? The machine is (of course) off warranty thanks for any useful advice anyone can provide.