Unable to save permissions at a specific folder

Hello,

I have a certain folder that when I would like to edit it's permiossions I receive a messege: "The permissions could not be save" at the same place where usually announce when the permissions has been saved.

This happen only at this folder, folders under the same path and at the same repository manager are working well. I receive this messege on every user I try to modify this folder's permissions, even with user who is the owner of this folder and even with the Administrator user of the portal.

Any idea why this happen?

roy