It might help if you tell us what operating system you are using, if its 32 bit or 64 bit.  And what release of Poser 6 you are on (what service packs, or hotfixes have been installed).  Other things that are useful include the video card, motherboard chipshet (for example the nforce4 drivers have known problems with SATA drives).

As bantha is describing you should check to make sure you have the latest and greated video driver for your video card from the nvidia or ati site (depening on your video card)

Shawn McCarthy
www.defyallchallenges.com