[Palmgren]

After making a clean reinstall of 10.3.9 om my PM G4 466 MHz (and subsequently adding saved library files from the previous installment), the keyboard and mouse sometimes suddenly become (and stay) unresponsive. All prosesses are running perfectly (playing songs in iTunes, fetching new mail, or whatever was in operation just before) and I am unable to find any crashreports after having made a hard restart.

Any suggestions how to fix the problem?

[Madrag]

have you tried plugging them into a separate USB port after the unresponsivness to see what happens?

Maybe your USB port might have some fault...

[Palmgren]

I think you got it right! I have tried to plug the USB in and out (or change port) when it gets stuck, and it helps in most cases!