Could you be more specific?  I see no options for texture buffer on any of the preference tabs.  The closest thing is texture spooling under imaging, scratch disk.  If that's what you're refering to, what setting do you suggest?  Under task manager memory usage, are you suggesting that MatCreator monitor the CPU and paging file usage while it's rendering?  What should you look for?  Carrara is rendering about 1/2 of the plane before it runs into the memory error.  Neither seemless nor interpolate is checked on the plane's shader.  It's just tiling at the default size (8x8).  Should seemless and interpolate be checked for use on an infinite plane?

Irene-