Rated 4 out of 5 stars

Rosherosh, It's not a bug.
you probably didn't activate the option to shut down firefox if the password is wrong/not entered.

If you did, look at the help, he says that addon is mainly to eliminate the duplicate prompts. the security is an addon so easily avoided anyway through firefox`s safe mode.

This review is for a previous version of the add-on (1.1).