Comment 36 for bug 240437

What I asked Xande to test should be interesting for you too:
One interesting test (for both of you) would be to start the scripts before starting users-admin, and to compare the startup times: start users-admin once, run it again and see the time it needs, then wait for 5 minutes so that the scripts to stop automatically, and restart users-admin to compare. The first time is needed so that the tool is loaded in memory, but it should not be taken as reference for anything.

You don't actually need to do anything other than starting and closing the tool, noting the (approximate) time it needs to be up. Does the users list appear the second time? Is it visible the third time (i.e. after waiting 5 minutes without using users-admin)?