Properties Dialogue Blank

I have been working on getting pay items assigned to my model in preparation for Automated Quantities. Everything is going fine, then I complete a model file and move on to the next only to find that nothing shows up in the Properties dialogue when I select something. I am forced to Exit ORD and come back and everything works again.

Does anyone know what causes this and if there is a workaround other than restarting ORD every time?