I had troubles rendering a simple scene, Poser freeze in many temptatives, so I opened Windows task manager to watch memory usage.
The scene in preview mode before rendering used 280M, when firefly started  to render at a realtive low size (600x720) in final mode strange things happened with the memory.

Here is the screen-shot. If you sum all the menory used by all tasks  including Poser it gives a total of 139M. If you look below in the task manager you can see Commit Charge 1472M.
The question is: Where are the missing 1.333 GB ???

Who have I to blame, Poser6 or Window XP Task Manager?!

Stupidity also evolves!