I would agree that shutting down Poser and rebooting it should get the memory back to what I would think would be more reasonable as you say.  But that is not working.  It's like there are cached files somewhere that I cannot clear.  Not sure where to look for this

Windows 10 - Poser Pro 2012 - 64Bit - 24GB RAM - 4 x 3.40 GHZ processor