um, can i be the first to say holy crap!?   you've been doing those renders on a box with 1GB of ram?  and only 1.87 GHz?  all those figures, all those textures, all those props?  all that transmapped hair?

i must be doing something wrong.  the computer gods definitely don't like me nearly as much as they like you. maybe i need to sacrifice an old drive and burn some incense. 

on topic, yes i've had this happen before, but i can't for the life of me remember how i made it stop.  not with Poser 7 but Poser 6.  just kept telling me i couldn't load textures when it obviously had the resources to do so.  it was so long ago, i can't remember how i got out of it, but i do know that it wasn't a persistent enough problem for me to need to ask about it.  so my guess is i just did the typical cleaning type stuff of clearing caches, getting rid of temp files, and letting it sit when off a while instead of just doing a restart.  and every now and then i do a search to find large files where my OS is, so i can get rid of nasty large things i don't need.  not much help, i know.