[plt-scheme] Debugging the lazy language

Final question of the evening...

I'm experimenting with the lazy language.  Now I've written some code
that works fine w/ eager evaluation.  I converted to lazy, mostly just
by changing module declarations to (lib "lazy.ss" "lazy"), and now the
code doesn't do anything.  I've peppered force ("!") statements around
but still no joy.  It uses the class system if that makes any
difference.

Is there any way I can debug program in the lazy language and work out
what is and isn't getting evaluated (and better yet, why)?  I
sprinkled a few printfs around and so far, no output.

Also, if there any better documentation than the terse doc.txt?

Thanks,
Noel