It's been a while, a couple of versions ago, but I have seen strange things like this on misc. user accounts.  When the user exits the client, the search settings they have active in that session is supposed to be saved on the server in their specific user attributes.  This way if the user logs onto another computer and opens the client, they will see their specific user settings, views, and searches regardless of the computer they are logged onto.  What I always did was go to the LF Admin console and reset the users attributes.  When you open the specific user's account, click on the attributes tab.  If you want to reset all attributes, click on "show system attributes".  Highlight everything in the pane and click remove on the right side, then apply at the bottom.  If you only wish to reset a specific attribute, such as search, in the middle of the pane, click the drop-down on subset and choose search, then highlight, remove, apply. The next time the user opens the client, they will be set to the default search options.