defmacro fails under DrScheme but not under MzScheme

[Hannu Koivisto <azure@iki.fi>]

Greetings,

Since loading my project under MzScheme (102/16) resulted to
"reference to undefined identifier: item" message without any
indication of where the problem actually is, I thought to try
loading it under DrScheme with language set to "Textual Full Scheme
(MzScheme)" because I've understood that there are some additional
debug facilities (such as source location recording) available
under DrScheme.  Unfortunately now the loading stops with a message
"...scheme-tools.scm: 24.2-24.10: reference to undefined
identifier: defmacro".  This file loads just fine under mzscheme
and it requires library compat.ss at the beginning so defmacro
should be available, but for some reason it doesn't seem to be.  I
browsed the manuals but couldn't find any explanation for this
behaviour.  Any ideas?

Also, would it be possible to enable source location recording and
other debugging facilities (for example, stepper) under plain
MzScheme?

-- 
Hannu