Version:           4.4.5 (using KDE 4.4.5) 
OS:                Linux

When starting KOrganiser (either stand-alone or embedded in Kontact), I frequently get a popup stating "Error while loading" and then the name of a calendar.
The calendars that this happens with are all calendars that are accessed using the GroupDAV protocol. If I later re-enable the affected calendar(s), then everything works fine.

When doing some exploration into the issue, I noticed that the popup came at about the same time as the first response from the server (which is invariably a "401 Unauthorised" response, because the first request never includes the user credentials)

Reproducible: Always

Steps to Reproduce:
Preconditions: Have an active GroupDAV calendar on a server that requires authentication.
1. Close KOrganiser and Kontact (make sure no parts of it are active in the background)
2. Start KOrganiser or Kontact

Actual Results:  
Popup "Error while loading <calendar name>"
Calendar has become inactive (unchecked in the list of calendar resources)

Expected Results:  
No popup
Calendar remains active