The cure is to restore factory default settings. Here's how:
1) Turn the printer on and wait until it comes ready.
2) Locate the control panel and press the On-line button to force the printer "Off-line".
3) Press the Menu button.
4) Press the down arrow until "Misc." appears in the display, then press Enter.
5) Press Enter again to select "Restore Factory Setup".
6) Press Enter when the "Factory Setup" question appears.
When you've done all this, the printer will display "Confirmed" and run a self-test. The printer will return to the ready state once the self-test is complete.