My company is currently transitioning into using PDM.  At the moment, there are two users who are testing out the configuration until we get everyone else on board.  All of the engineers in my depart have PDM installed, they just aren't logging in

A problem I'm running into is we are randomly losing our license, and other users are automatically getting logged in.  I can be working with a dozen or so files when I receive a message telling me "Failed to obtain a license for SOLIDWORKS PDM Professional.....".  I don't have automatic log in enabled in the PDM Administration tool, so I'm not sure whats causing this, or what I can do to prevent this.

Is there some other setting I'm missing that disables automatic log ins?  Why am I losing my license in the first place?