[imp] Dimp - confirmation button for meeting invitation not working in message preview

[Alexander Bruckner]

Hello,

I am currently testing the following versions:

- Horde: 3.2-RC1
- Dimp: H3 (1.0-RC1)
- Imp: H3 (4.2-RC1)
- Kronolith: H3 (2.2-RC1) (run Kronolith tests)

Installed on a Debian Etch server with Php 4.4.4-8+etch4.

My problem is, that the button to confirm a meeting invitation (with the 
  options  ('Accept and add to my calendar, Add to my calendar, etc...) 
does not work in Dimp's message preview.

When I click the button a download window pops up trying to download the 
file "ShowPreview" of type "text/x-json".

I think it has to do with the form action not being generated correctly. 
The form action is: /dimp/imp.php/ShowPreview .

When I double click the message the confirmation button works in the 
displayed message (message displayed in the pop up window). Here the 
form action is:
/dimp/message.php?folder=INBOX&thismailbox=INBOX&uid=1234

Is this a known problem, or a problem with my test installation ?
(I have also tried the latest nightly with the same problem)

best regards,
Alexander Bruckner