It's sounds like one of the Vista UAC peculiarities.  For me, it was a constant battle with Vista and every graphics program I had.  Finally sidegraded to WinXP 64

There are a few threads around, but I used some of the not recommended techniques like turning UAC off.  Also installing poser in a directory other than "Program Files/...whatever" will help.  Vista and Win 7 both have the "protected virtual store" which put blank copies of necessary files where you don't expect them.

You will also have to init the figures using the "DzCreateExPFiles-(Figure Name).bat" found in Runtime/libraries/!DAZ