[Orgmode] Headline with 2 timestamps is displayed only once in the agenda

[Tassilo Horn]

Hi all,

I have this entry in an org-file.

--8<---------------cut here---------------start------------->8---
** Übung Grundlagen der Softwaretechnik (B 016)        :teaching:
   <2009-04-22 Wed 08:30-10:00 +1w>
   <2009-04-29 Wed 10:15-11:45> (Für Hannes übernehmen)
--8<---------------cut here---------------end--------------->8---

I expect it to be displayed every wednesday after 2009-04-22 for
08:30-10:00 and on 2009-04-29 it should be displayed twice: one at the
usual time and one for 10:15-11:45.

But the agenda shows only the regular entry (08:30-10:00) and omitts the
exception.  If I reorder the timestamps, so that the exception comes
first, only the exception will be shown on 2009-04-29.  Every other
wednesday shows the regular repeater date.

What do I have to do to make that entry showing up twice on 29th April?

BTW: Is it possible to specify an end date for repeating events?
Currently I just deactivate timestamps when they're obsolete, but
sometimes I'd like to check which appointments I had some month ago.

Bye,
Tassilo