I asked this same question recently. I had forgotten to re-install the Pro-Pack Memory update patch when I installed Poser on my new system. Installing the patch solved the problem at the time. The problem has reappeared twice since then and disappears when I defrag the drive Poser is on.

Expert in computer code including, but not limited to, BTW; IIRC; IMHO; LMAO; BRB; OIC; ROFL; TTYL. Black belt in Google-fu.