[vtkusers] Can't cache Resliced image

[TJ Wilkinson]

I'm working with a 3D volume about 250 MB in size.  In order to pan
through slices faster, I have a button to call UpdateWholeExtent() on the
reader, which works well.

However, when I try to look at the volume at a different angle via
ImageReslice, I am unable to pan quickly.  I thought perhaps that the
filter was the part of the pipeline that was taking some time, so I
UpdateWholeExtent for the reslice filter, but I still am unable to pan
through slices quickly.  

Looking at my memory usage, it jumps, as it should, after hitting
UpdateWholeExtent, but when I try to change slices, memory usage jumps
back down.  Can anyone tell me what is going on, and how I might be able
to cache the resliced images?

Thanks.

TJ