[plt-scheme] minor WHEN and UNLESS question

This is a rather minor issue I noticed in the documentation:

According to http://docs.plt-scheme.org/reference/when_unless.html,
the results of evaluating WHEN and UNLESS are ignored. According to
http://docs.plt-scheme.org/reference/when_unless.html, the result is
#<void> (which is of course ignored by the REPL). Evaluating the
following expression in module language
shows that actually the result of the last expression in the body is
available at least in some cases; didn't test extensively.

> (+ 1 (when #t (+ 1 2) (+ 3 4)))
8

>(+ 1 (unless #f (+ 1 2) (+ 3 4)))
8

So the question is...which version is the correct one? Ignored,
#<void>, value of the last expression in the body?
--Yavuz