VEr 8.02 - Deleting Members

I just registered a new version 8.02 Forum today and licensed same for the website www.neopc.org. The strange part of the new installation was that it already contained a number of members and messages. I am in the process of cleaning up the old information and I am having a problem getting rid of some members. I was successful in removing some, but not all.  I get the following error message:

The problem that I expressed was a result of using the Forum software to attempt to delete unwanted members. Again, the strange thing is that it performed well for a number of them, but there are a few it just develops the error report noted in my original message.

i am also receiving this error when I try to delete a few members. These are members who don't even have any posts to delete. I don't want to remove them all, just a few.

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Microsoft JET Database Engine error '80004005'

The changes you requested to the table were not successful because they would create duplicate values in the index, primary key, or relationship. Change the data in the field or fields that contain duplicate data, remove the index, or redefine the index to permit duplicate entries and try again.

/forum/delete_member.asp, line 136
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I am all set now - everything working just fine - thanks to all of you.