Hello. New to the forums, but hopefully not asking a question hammered by others already. I have a PowerMac G4 (Dual 1.42) running OSX 10.4.7. Since the latest OS (Tiger), I've been having problems turning on the computer after shutting down. About every other time I shut down, upon trying to turn the machine back on (using either the power button on the Apple display or the power button on the 'mirror-door' on the front of the comp') it recognizes my pressing as the light goes bright (under my finger), but the unit won't turn on. This also happens when I put it to sleep. While in sleep mode, I press a key or move the mouse (or click the mouse) and the unit shuts down. I press the power button(s) and the same thing happens where it recognizes that I'm pressing the button (the light illuminates), but the unit does not power up. The only way I've been able to turn it back on was to pull the power cord for at least 10+ seconds, plug it back in and turn it on with either the monitor power button or 'mirror-door' button. I'm fearful this is not good for pulling the power cord in and out several times a day. Any suggestions or ideas would be appreciated. It feels like a software problem as it didn't do this until I upgraded to Tiger. Thanks in advance.