How to Reset a Forgotten Password
You can reset your password without having to reset factory defaults using a hidden menu available from the status screen.
To get to the status screen, press the Menu button. Then select System -> Status. With the status menu on screen, press these buttons in order: red, green, yellow, blue, yellow, green, red.
A 'Hidden Menu' will appear, from which you can reset the password to 0000.
A nice side effect of this procedure is that you can find out the MICOM version (equivalent of the BIOS for the Hummy) from the IRD to IRD menu. Do not attempt to change any other options from this menu.
Originally posted by FB
With thanks to Marc Davis for this tip.