Comment 1 for bug 879337

This is not likely to be a thunderbird problem at all, and if you check the service status there is some disruption with contact sync (https://wiki.ubuntu.com/UbuntuOne/Status).

Opening ~/.local/share/desktop-couch/couchdb.html in your browser and verifying the "contacts" db against what is displayed in Thunderbird will help pinpoint where the problem is. If the contents match (ie, if there are no contacts shown in the PC in your office), then the problem definitely is not with Thunderbird. If the contents don't match, then the problem *could* be with Thunderbird, but is more likely to be a problem with evolution-data-server.