[otrs] Not possible to add a note in OTRS 2.1.4

Hi, We have just upgraded from OTRS 2.0 to OTRS 2.1.4 and now is not possible to add a note to a ticket if altough you have rights for adding notes. You also need to be 'owner'. That's a functionality that was working in 2.0 version. Please, could you tell us if it's needed to change something in the SysConfig? Thanks in advance, Josep