Tim,
Something odd is going on with the Tracer -- it produces an image somewhat bigger than 6Mb, which starts up ok and saves back to 4-ish MB. Rather spoils the 'coffee-break garbage collector' story doncha think? It seems to be a recent problem, as older images clone same/smaller as appropriate. I though it might be related to the Display size/depth, but seem to have ruled that out. Maybe the WeakArrays need more careful cloning?
This might be a problem (I actually never used the tracer) but I'd think that the tracer probably doesn't compress any forms which makes quite a bit of image space.
Andreas