The latest posted firmware is 2.0.23 for the 3cnj220.
I am also trying to find out how to reset the password.
I opened the unit and find a push button. In fact, there is a small hole just to the left of the printed symbol, presumably to insert a paper clip. Though it looks like a reset button, I tried to hold it for 30sec while powering unit up and hold it 30sec during operation. The unit reset but did not clear the password.
So what I am saying is that it is not necessary to open the unit. Just put a paper clip or better a non-metallic object like a toothpick through the pinhole to reset the unit.
The password is needed to change configuration or update the firmware, so it would be nice to be able to factory reset and clear the config information.