outlook calender randomly stops working

[mc123]

Hi,

I am running exchange 2003 SP2, and outlook 2003 SP3. I have one user that
is experiencing issues such that at random times the calender won't allow any
additions. I notice that when exiting outlook, outlook is still running, and
I will have to kill outlook.exe before calender starts working again. there
is no pop-ups when attempting to add calender, simply won't add anything
until outlook is restarted or rebooting the machine.

Any idea of what may be causing this? I googled this and found that others
with similar issue has attempted to clreaview, repair, re-install, go to SP2,
but have found no solution to this?

Thanks for any suggestions or if you have had past experience with this.