Jeff, what were your scene settings coming out of Poser 6? The one problem I've come across is when I have the Preview set to Open GL and the accumulation set to Hardware instead of Software. That forces your video card to hold all the info and it can really slow ya up if you don't have a power card installed. If you have that switched on you may want to turn it off and try again. 

Also, keep in mind the UNDO levels. Poser has to remember all this stuff now so as a personal (ie. NON-OFFICIAL) suggestion, I'd lower the undo levels when working on larger scenes. This comes from experience using 3D Modeling applications.