Folder structure going crazy with two sent / gesendet folders

[Benjamin Eckl]

Hey community,

I'm working with:

Kolab Groupware Server Version
2.3.2 Community Edition

Kolab Groupware Server Component Versions
amavisd: 2.5.3-20080101
apache: 2.2.17-20110328
clamav: 0.97-20110301
db: 4.5.20.2-20070628_kolab1
imapd: 2.3.16-20110428_kolab1
kolab-fbview: 1.2.0-20081227
kolab-webadmin: 2.3.2-20110603
kolab-webclient: 1.2.6-20100122
kolabd: 2.3.2-20110531
openldap: 2.4.23-20110308
openssl: 1.0.0d-20110222
perl-kolab: 2.3+git-20101212
php-smarty: 2.6.20-20081212
php: 5.3.6-20110601
postfix: 2.8.3-20110531
spamassassin: 3.2.4-20080107
sqlite: 3.6.22-20100309

While doing tests for real life use, I got confusing behavior in folder 
structure.

I did sync with synckolab (1.5.2) for thunderbird 3.1.13 (+lightning 
1.0b2) and z-push with nokia E71.

Now the components do not know anymore where to save sent mails. I have 
a "Sent" folder and a "Gesendet" folder (german translation of sent). 
There is no chance to delete any of them. Firefox i.e. cannot 
differentiate between both, Sent gets automatically translated but both 
folder are displayed and get special icons. Sometimes emails are saved 
in sent and sometimes in gesendet.

Anyone an idea how to solve this issue or help me debugging this 
misbehavior?

Thanks!
Ben