I've had the same problems - my year long fight with this issue has rendered these solutions...

I dont run anything else while poser is running

I keep a backup set of my preferences

when it goes all non responsive - I throw out the preferences - clear out my trash - restart my machine - restart poser - see if it responds when I try to delete a simple prop - if it does - I close poser - put my back preferences in place - and go from there

D

I came, I rendered, I'm still broke.