Deleting Reservation from Resource Reservation DB

I recently upgrade from Domino 6.5.3 to 7.0.3. When One of my users attempts to delete a reservation from the RR Db, the get the following error:

You have selected repeating reservation that was created in a previous version of Notes. Deleting part of this repeating set is not supported. Do you wish to delete the entire repeating set?

The user is wanting to end only one of the meeting instances, not all. Any ideas?

Thanks!