Recently I've noticed a lot of these random lines appearing horizontally across my screen. It usually happens in Safari, but the one here was in Fireworks. The thing is though, I took a screen shot of another one but the line wasn't there in the screen shot. Could this be a graphics card issue? I have a ATI Radeon X1900 XT. Also, twice in the last few days my screen has completely frozen. I couldn't move my mouse, nothing moved on screen, but I could still control iTunes fine with my keyboard... so I guess the computer had completely frozen, just the graphics. The only way I could get out of this was just to hold the power button till it went off After the second crash like that, when it'd started up again, it crashed again. Almost the same, but the mouse was still moving. After about 10 minutes waiting for it all to come back to life I killed the power again, fine after that. Any ideas on what could cause all this?