duplicate entries created when sharing calendar

[shak]

i have just recently had to move a user to another
machine, so imported all the emails and caledars from the
old pst file.

we share the calendar between a few users, but once we
start sharing the calendar, entries that are in the
calender begin to duplicate and then triple. i have
checked for viruses, performed nfcleans etc. can any body
advise as to why the entries are doubling up?