I recenty had a VUE problem trying to render larger complex images with 5 poser characters and other stuff in the images with Vue but found a solution for my case.  I thought it was a memory problem because I could not render larger images.  Additionally, my system would also crash after doing several renders of the same image, as though VUE was snowballing away my memory.  However, I found it was not memory in my case but was an accumulated rise of temperature in my CPU; which I was able to fix.  Check out my thread below:

http://www.renderosity.com/mod/forumpro/showthread.php?thread_id=2705718