Conserve memory gives black output

Hello everyone,
When checking the conserve memory box in the MR render processing tab, the 
only output I get is a black screen.  I haven't seen anyone else posting 
about this sort of problem, so I am hoping there is a simple setting I am 
missing.  Has anyone else had this problem?

Thanks for the help.
- Eric

P.S. I am also writing some custom shaders that create frame buffers within 
Mental Ray, they work great when doing a normal (without Conserve Memory) 
rendering, but gives a bad output that is not even recognized as an image 
when using the switch.  Maybe that will give someone some extra insight?