ps-print doesn't omit invisible text

["John Halton" <johnhalton@gmail.com>]

I'm using an emacs mode (tagging.el) that uses invisible overlays to
hide text that doesn't match a given tag (a la folding.el).

However, when I print out the buffer, I get the whole buffer including
invisible text, not just the text displaying on screen. By contrast,
quick print via web browser (from the File menu) only prints out the
visible text.

Looking at the ps-print.el file, it looks like ps-print does have the
ability to skip invisible text when printing, but I'm too much of a
LISP ignoramus to understand why it should be failing to do so in this
instance.

I'm running Emacs 22.0.91.1 under Windows (work PC...), installed from
EmacsW32. However, the same issue also occurs in Emacs 21.

Thanks,

John