I have my own server (running ubuntu 12.04) on which I installed ownCloud and were able to successfully synchronize my Calendar via CalDAV. But when trying to synchronize my contacts with CardDAV, nothing worked. Everywhere I searched, all I could find was using SOGO-Connector which didn't work at all.
By the way: One thing SOGO-Connector did, was asking me twice for my master password every time I started Thunderbird.
Is this an ownCloud-specific (v. 4.04) problem?
If anyone has a solution wihout ownCloud or without cardDAV in general, this is fine, but it shouldn't store my contact data anywhere else than on my server (that means no cloud storage solution).
It may help to know, that I have a working SparkleShare synchronisation.
EDIT: Now using Radicale instead of ownCloud but with the same problems.