Hello to everybody!
 
I just made a tool to reserve terminals in a computer lab. It has two basic
functionalities:

- Make a reservation (calls the method "createInObjectManager")
- Cancel a reservation (calls the method "manage_delObjects")
 
As a manager user, I can make reservations as long as I want; however,
when I cancel a reservation and try to make another reservation, I get the
following error:
 
Zope Error
             Zope has encountered an error while publishing this resource.
 
             Error Type: AttributeError
             Error Value: _setObject
 
Does anybody knows how to solve it?

Thanks in advanced,
Josef.