[racket] memory issues

New numbers with a fresh install of 5.2:

starts 200MB
open 5 buffers 230MB
first scribble 300MB
compile all buffers 450MB
recompile first 530MB
all again 580MB
all again 650MB
all again 620MB
all again 680MB
all again 700MB
all again 720MB
all again 660MB
all again 690MB
all again 710MB

Interestingly, the numbers are around half of what I had yesterday with the old install.
But the tendency is quite similar. A constant increase and then stabilize around 700MB (which yesterday was 1.3GB, causing troubles on my machine). The whole experiment was done in 20 minutes or so, leaving time in between compiles.

Note that I have repeated the experiment of yesterday with the previous install, with very similar results (800MB after first compile of 5 buffers, 1GB after first recompile). In less than 5 minutes.

This yields two (probably very naive) questions:
- how come the previous install behaves this way? it's true I have activated online syntax check before, but it is now disabled. Can it have left an impact?
- why does compiling the same files again and again mean taking up more memory? are there caches or other data which DrRacket keeps hanging on to?

Thanks,

-- Éric