I have a problem that comes and goes for no obvious reason.  When I go to EPDM and double-click a file (part, assembly or drawing) it will not open unless I have it checked out.  (Which if it is released, I can't do.)  Solidworks will start and it will look like it is going to work, but it doesn't.  I also can't open it from Solidworks.  If I start a new assembly, then I can insert it. 

Throughout the day I keep trying it, and at some point during the day, it will usually start working like it should.  I can't figure out what causes it to start working.  And when I come back the next day it starts acting up again.  Any ideas where to look for help?