Past calandar appointment keeps re-appearing

[jodala]

Past calandar appointment keeps re-appearing even after
deleting it.

 

[Robert Crayk]

Starting Outlook with the cleanfreebusy command may help, go to Start > Run

 

[Nikki Peterson [MVP - Outlook]]

Just on the off-chance that the cache is messed up
I would try deleting ALL OST files if you find any...

Close Outlook
Search the hard drive for
*.ost
(be sure to search in hidden files)
Then delete it (or all that you find)
Open Outlook

A new OST file will be created when you open
Outlook.

Also you may want to look into the following possible solutions
There are several solutions offered on this page
(not just the scanpst):

For more information on how to repair a damaged Personal
Folders PST file:
http://www.slipstick.com/problems/scanpst.htm