Importing Duplicate Emails

[George]

I am attempting to import various messages from a number
of PST files, however, although I select do not import
duplicates, it still appears that duplicates are being
imported. Using OL2000 w/sp2. Also, I have attempted to
export, select do not export duplicates, and duplicates
are be exported.

Any suggestions/ideas would be appreciated.

Regards,
George