Can't delete declined meeting requests Array out of bounds

Outlook 2007 running in Vista.
When I decline a meeting request or when someone declines my meeting
request, an email message arrives on the machine of the person who sent the
request indicating that the invitee declined. However the message declining
the invitation cannot be opened or deleted.

Any attempt to open or delete the decline message results in a box entitled
"Microsoft Office Outlook" with a message "Cannot open this item. Array
index out of bounds." With an OK button and a request whether this
information was helpful.

Any ideas how to solve this problem and delete these decline messages.