It's 32 bit, 4 gig. I may have added a shader, like today, ive been trying to add materials to the books on the book shelf in that bee scene Ive been doing. I rendered on loading - about 7 minutes. Then I made 5 or 6 new lambert materials, each with its own texture, just the spine of a book, add one to each book. So I click render again. Exactly the same, just 6 books, 6 tiny books, have a new lambert on them. 1 hour 40 minutes.

I have vista, and I have other stuff open at the same time, but it's happening when I don't have stuff open aswell. And whats open isn't really heavy duty, Im not downloading, or surfing the web, I might have a couple of notepad files open, or photoshop on standby. But it's why one minute, generally after loading maya, it renders without trouble, then next time, its like cluttered itself up and takes so much longer. I've been restarting my computer to reopen maya cause the patterns emerged that the first render is reasonable, and thereafter my computer seems to struggle. I don't want to sound immaturely impatient, I just don't understand the drastic fluctuation.

I would say that I dont think my scenes that 'expensive' because from google-searching I've done people seem to get the memory issues when they're in the millions of polys, and Im nowhere near that. But then I guess I have some particles, and a couple of bits of n-cloth. The render settings are pretty high, but they have been throughout.