Meeting Request Issue

We have a user who is sent a meeting request, and:

1. exchange 2003 sp1 message tracker indicates that it is successfully
delivered to the mailbox
2. the user does not get the email about the meeting
3. the meeting will sometimes show up in the calendar (usually after he
makes another meeting to send to another user)

has anyone seen this as it happens in the outlook 2003 client and OWA. i ran
the:
Outlook.exe /cleanviews /cleanreminders /cleanfreebusy

but that did not do anything. his outlook works otherwise. i had this for
another user and ended up backing up their mail to a PST, dropping the
exchange attributes, and recreating the mailbox, and reimporting again, and
that worked..but i would like to know if there is another fix as this is
puzzling

thanks. steve bouse/answerthink mis