Duplicate Calendars

[Jamie]

I have a member of staff that has two calendars in Outlook, their regular one
with all the info in and a duplicate calendar that is blank and is showing as
the default calender. Does anyone know how to return the populated one to
default and delete the blank calender. When we try to delete the blank one it
says you need administrative rights, however the user who has administrative
rights has tried and failed.
This problem came about after upgrade from Office 2000 to Office 2003

thanks in advance