Just as an aside, the PV+ system really bites when it comes to user accounts and passwords and permissions; especially if you ever have to backup/restore applications.
If you are only trying to control access to certain functions (like Maintenance / Setup screens) and such, I find it easier just to use a numeric or string tag in the PLC and PV+. Idea being, you write a number to the PLC as a 'Password', and if it equals the target value in the PLC, you set a bit to TRUE, which the HMI then reads to enable/make visable the password protected access.
To clear the access, just have a button to write 0 to the password tag, or have a timer in the PLC that automagically clears it.