Contacts in contacts.app disappear on relaunch / no editing possible

I use contacts.app in mountain lion to manage my contacts. It synchronizes nicely with my iPod touch via iTunes. I don't sync them with iCloud and the contacts aren't on iCloud. iCloud is completely off. Contacts.app grabs my contacts from facebook, but the following problem also exists when logged out of facebook (preference pane).

Since I installed Mountain Lion, every time I add a new contact, it disappears on relaunch of contatcs.app. It doesn't even sync with my iPod when connected. Additionally, when I want to edit a contact and click 'done' it doesn't save the new information.

Can someone give me an advise, please?