So I did read though the previous forum relating to this problem. None of the posters were having the exact issue I am, and I could not find a solution within. my hardware: powerbook G4. 1.33GHz Power PC. (upgraded to) 2GB DDR SDRAM. (just upgraded to) 320GB WD HDD my OS: Just installed 10.4.11 Here's the scenario (I hope someone can help): Several months ago my poor baby took a dive off a counter onto the tile floor, while running. Never before this did I see the "Kernal Panic" restart screen. Immediately following the fall, I get the error if the computer is bumped, moved or if I put weight on the keyboard (palms). I feared it was a HDD issue so I hastily replaced the toshiba 60GB HD with a WD320 HD. And at the same time I upgraded from 10.3.9 to 10.4.11. The computer seemed fine for a couple weeks, now I am getting the error again with increasing frequency. Mostly when I put pressure on the keyboard (palms). What I tried: new HD, new OS, checked the RAM to see if it had come loose in the fall. Could it be my video card? Is it more likely hardware or software?