Thanks for your answer,
half of the problem is done : for one of my locked documents, I've recreated a fake qvw with the same name and I could unlocked it.
For the second (which is a QlikTech exemple) one, there is a \\ in the url and so the Enterprise Management console consider that
C:\DOCUMENTS AND SETTINGS\ALL USERS\APPLICATION DATA\QLIKTECH\DOCUMENTS\\FILMS.QVW
isn't the same file than
C:\DOCUMENTS AND SETTINGS\ALL USERS\APPLICATION DATA\QLIKTECH\DOCUMENTS\FILMS.QVW
But I don't where does that \\ come from ???
I've tried you're second solution and I've erased all PGO and META file but It didn't solved the problem.
Do you have any other idea ?