Lock in Integrated Planning

Hi,

I'm using Integrated Planning and I have a problem with the Lock, when a user start a report a lock entry is created but when the user close the report the Lock entry does not dissapear and when the user come back to the report the system say that the entry is locked and I have to go in SM12 to delete the lock.

How can I manage this lock problem.

Thanks a lot fore your feedback.

Eric