I have had a G4 400mhz zif around that I got a couple years ago. I decided to put it in a 300 mhz Yosemite I have that is running 9.2.2. I installed the G4 enabling patch and put in the zif. I put a cooling fan on top of the heat sink. Whe I started it up, the interface acted squirrely. The cursor diappeared unless being moved. All the icons on the desktop flashed in sequence if I double clicked on one of them and the menu bar windows would not stay open when the mouse was released.
I changed the jumpers on the board to make 400mhz restarted and the situation continued. Also some of the start ups would leave the mouse locked up and I think the computer frozen. Restart and the freeze up might be gone.
After letting the machine run for about an hour, all these anomolies went away. I suspect that they may very well come back on restart after it has cooled down though. Any thoughts?