Error came back after a few minutes. Logging off seems to fix it, but dont know how long for.
Uptime is 21 days. After checking the event log there are some "app did not launch in alotted time" events for calendar and mail and windows error reporting seems to have sent files to MS related to these events. After logging out and back in both apps seem much snappier to start.
Edited by Banger (Sun 06-Apr-14 00:55:02)