Calendar not running on desktop

[Dave Morley]

STEPS:
1. Install the ubuntu-core-apps ppa
2. Install the calendar-app
3. Try and start it from the icon
4. Run calendar-app from the terminal

EXPECTED:
A running calendar

ACTUAL:
On clicking the icon nothing happens, on starting from the terminal I get:

davmor2@stryder:~$ calendar-app
Fail to connect with client Unable to connect to 'Tasks': Cannot open calendar: Authentication required: {
 "error": {
  "errors": [
   {
    "domain": "global",
    "reason": "insufficientPermissions",
    "message": "Insufficient Permission"
   }
  ],
  "code": 403,
  "message": "Insufficient Permission"
 }
}

(qmlscene:6673): GLib-GObject-CRITICAL **: g_object_ref: assertion 'G_IS_OBJECT (object)' failed

(qmlscene:6673): libecal-CRITICAL **: e_cal_client_get_view: assertion 'E_IS_CAL_CLIENT (client)' failed

VERSIONS:
Calendar-app: 0.6bzr703vivid0
Desktop: Vivid