You sure you can't crosspost? Usually it's just a case of typing the various
newsgroups in the appropriate place, separating them with commas or
semi-colons.

And while there may not be any explicit rule prohibiting multi-posting, that
doesn't mean it's not preferred that people cross-post. "Help on the
Web-based Newsreader", for Microsoft's web-based interface, at
http://msdn.microsoft.com/library/gallery/components/wn/2/locales/help_en-US.htm
includes instructions on how to cross-post.

What is your reader, exactly? (since it's not likely a function specific to
the reader)

Whilst the advice is well-intended, there can be occasions where the advice is
over-the-top, usually annoying only the most regular of repliers.
Nevertheless, it is well-intentioned advice. Because I only read a few
newsgroups, I don't know, if you multi-post, whether you got a satisfactory
answer or not.

Since you like to multi-post (ie without cross-reference), see recent
occurrences of this problem and discussion in either this or other newsgroups
(damned if I can remember! alrighty there's a similar recent example in
.security)

Chris