If adding more RAM doesn't help, I don't know what will.  I've spent a lot of money on Vue over the years--I just upped the RAM to 16 gb--and if that doesn't work I'm about to give up on Vue.  I have Cararra--though the natural landscapes aren't as impressive I've yet to have it gag on a Poser figure once.  I might also try Collada import, perhaps that will simplify the figures enough so that they don't hog all the memory.  I might also try older figures with simpler maps, like Michael 2.  Boy it sure can be frustrating at time.  I have a 2.6 ghtz i7 processor, a Nvidea 9800 series video card with 1 gb ram--so if it doesn't work nicely now I will assume only a very powerful Workstation computer will do what the lovely expamples I see on the Eon website will do the trick and I don't love Vue that much as to upgrade my whole system.