Same happened to me now. Except that I don't have any backup on the device. That shouldn't matter much, though, as all my contacts are synced from my PC to the N9 via my Nokia account. Or so I thought.

After the tracker-reset the contact list was empty. I started a sync via the Nokia account. That took a while, no errors or other strange things. All went well. Still, the contact list is empty.

Next try: delete Nokia account, re-boot the device, re-add Nokia account, sync. No difference, contact list remains empty.

Next idea: Go online with some of the instant messaging accounts that populate the contact list. Now I at least get an error message saying something like "contacts could not be added". (Translating from German here.)

I don't understand this. I do realize that removing the tracker databases deleted the contacts from the device - but why on earth can't I add them again from the server?

Are there any other config files or settings that I should try to delete/change so that the contacts application returns to its original state?