problen with .psa

[Felipão]

Hi, I have four backups .psa from plesk 8.3 corrupted, and i can't restore this, i opened this files with winrar but winrar not extract this, is possible extract files who are not corrupt?

 

[Felipão]

details:

I have six backups from plesk ".psa" four corrupted and two working fine, but backup working fine is from 05/05/2010 and corrupted is from 06/13/2010, and i can't restore this with plesk corrupted, i opened this files with winrar and see all custumer files, but winrar not extract this becase corrupted, is possible extract files? if i try restore any file corrupted i see "can not find central directory".