I'm getting more and more covinced that bryce has a memory-leak - i've experinced that after opening bryce (and closing afterwards) many times in a row , with renders in between i get less and less free memory - but that doesn't show up in the task manager because the stolen chunks of memory don't belong to any process any longer, but still are unavailable to the system. That could be a part of your problem (if i'm right in assuming the memory leak)