[Orgmode] Bug? Archived tasks appear in icalendar export

[Denis Bueno]

I'm using GNU Emacs 22.0.92.2 (powerpc-apple-darwin8.8.0, Carbon
Version 1.6.0) of 2007-01-18, and org-mode 4.71.

I have tasks in an org-mode file that look like

* TODO OD ch 3                                  :2340:ARCHIVE:

When I do C-c C-e i, and load up the ics file in iCal, I see that
entry in my list of Todos. I think this is a bug. What do you think?

Thank you.

-Denis