chwala trouble on kolab 3.3 with ssl

[Matthias Busch]

Kolab 3.3 on Debian 7.6 x64, single domain, ssl with signed certificate

I have trouble with chwala which appears not to be working.

On Webmail, I don't see a Files folder (it exists). I can not create a 
new one. If I create one in the folder-settings (for files), it does not 
show up. Since there is no folder, I can not upload/use chwala

If I try to use https://domain.tld/chwala directly, I get a login screen 
but can not login "internal system error" (translated from german)
(I tried cn=Directory Manager as well as cn=user and 
cn=user,dc=domain,dc=tld )

the log ( /var/log/chwala/errors) shows (but only when trying to login 
at /chwala)

[06-Nov-2014 10:39:29,000000 +0100]: <iubl5p31> PHP Error: Login failed. 
Unable to connect to ssl://domain.tld:443. Error: 
stream_socket_client(): unable to connect to ssl://domain.tld:443 
(Unknown error)
stream_socket_client(): Failed to enable crypto
stream_socket_client(): failed to create an SSL handle
stream_socket_client(): Unable to set verify locations 
`/etc/ssl/domain.tld/ca.pem' `(null)' (POST)

Everything else seems to be working flawlessly.
My certificates (single domain, signed by "official" ca) are working for 
apache2 as well as imap and smtp (all ssl enabled).
it seems I also changed the ssl settings correctly in 
/etc/roundcubemail/config.inc.php for /webmail
The location for the ca.pem should also be correct (i.e. the file is there)

After looking around a bit, this seems to have been a somewhat common 
problem when 3.3 was released. looking at the bug reports and my files, 
the suggested changes/patches have already been applied to my setup

I can post config files if need be.

Please help. It will be appreciated!