may I help.
Worrying about the argument passed. This is for the readOnly parameter.
EDIT: Steps I followed: added a new user
> db.addUser("admin","firstpwd") { "user" : "admin", "readOnly" : false, "pwd" : "40a84fcba954c8924d277f23b0f880b1", "_id" : ObjectId("51966ec8c7ad876ba0319438") }
Output
> db.auth("admin","firstpwd") 1
change Password
> db.addUser("admin","secondpwd") { "_id" : ObjectId("51966ec8c7ad876ba0319438"), "user" : "admin", "readOnly" : false, "pwd" : "82f4e416844349418281a3eca1cf6082" }
Output
db.auth ("admin", "secondpwd") 1
MongoDB Shell Version: 2.4.3
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