I have P8 on five 'pooters and PP2010 on two, all running fine.  I have a mix of WinXP 32bit, Vista 32bit, Vista 64bit.

And how does P8/PP2010 preview tiled materials on your machine?  Does it show one instance of the texture image across the whole material zone (i.e., untiled), or do you see the materials properly tiled in preview?  Needless to say, being able to see just where the edges will line up is a great benefit when dialing in material settings.

SreeD preview - tiling is lost

OpenGL preview with hardware shading used - materials are properly tiled:

Look at your settings in the render settings, preview tab:

Poser 12, in feet.  

OSes:  Win7Prox64, Win7Ultx64

Silo Pro 2.5.6 64bit, Vue Infinite 2014.7, Genetica 4.0 Studio, UV Mapper Pro, UV Layout Pro, PhotoImpact X3, GIF Animator 5