unexpected behaviour of the add user drop-down when switching windows/tabs

[FB-MfN]

Description

When switching between windows/tabs, while searching for users, the drop-down menu refreshes in between

Steps to reproduce the issue

1. +Add user
2. search for user
3. switch window/tab and go back

What's the expected result?

• drop-down with selection according to search string
  

What's the actual result?

• drop-down with all available users

Additional details / screenshot

[cannedit]

I consider this a minor issue which we can take care of later on.