iceowl extension not working with icedove

["H.S." <hs.samix@gmail.com>]

Hello,

I just noticed that Debian has iceowl-extension package. I removed 
lightning extension that I was using (I had installed it from within 
thunderbird and thus was not a system wide install), and installed 
iceowl-extension:
$> sudo aptitude install -V iceowl-extension
..
..
The following NEW packages will be installed:
  iceowl-extension [0.7-2]
0 packages upgraded, 1 newly installed, 0 to remove and 3 not upgraded.
Need to get 1157kB of archives. After unpacking 4219kB will be used.
Writing extended state information... Done
Get:1 http://gulus.usherbrooke.ca testing/main iceowl-extension 0.7-2 
[1157kB]
Fetched 1157kB in 3s (318kB/s)
Selecting previously deselected package iceowl-extension.
(Reading database ... 244729 files and directories currently installed.)
Unpacking iceowl-extension (from .../iceowl-extension_0.7-2_i386.deb) ...
Setting up iceowl-extension (0.7-2) ...


But after installing it and restarting Icedove, the calendar is not 
being shown in the mail client, it is as if the extension was never 
installed. What am I missing here?

$> dpkg -l icedove* iceow* | grep ^i
ii  icedove          2.0.0.14-1       free/unbranded thunderbird 
mail/news/rss clone
ii  iceowl-extension 0.7-2            Calendar Extension for 
Thunderbird/Icedove

This is on Debian Testing fully updated.

thanks.