[plt-scheme] Appalling performance of DrScheme on Windows

I also (on mac mini, os X 10.3, 512MB) get this sort of behavior: if I
leave it open for a few days without touching it, the response time
gets awful, and I then end up just quitting and restarting.

I downloaded v350 yesterday and left it open; when I went back to it
now, (+ 2 2) took about 30 sec of GCing to run, but then once that was
done it runs smoothly.

I also have Firefox (with Gmail) open all the time, so I'm not sure if
that might be a memory hog culprit too.  I tend to have a lot of open
tabs ...

I'll monitor more closely what leads to the DrScheme slowdowns now
that I see that other people have similar problems.

--Joshua Zucker