Just recently, the 2 USB ports on my display stopped working. It is hooked up ADC to a Quicksilver G4 933, with 1.25 GB RAM, (2) 60 GB drives. The back USB ports on the tower work just fine. The only thing I did recently was update the system from 10.3.8 to 10.3.9
I reseated the ADC connector and restarted but no change.