restore change user/group files/directories

Hello,

i had a un expected behavior after restoring a directory : some files and=
 directories within change user and group owner on the backup server, it =
switches from user used for backuping to the real user (i mean from the p=
roduction server) : www-data (web server user).
in this situation, i can't restore any backup in this directory.

The last backup crashed because of permissions : i change the permissions=
, and restart, so i hope it will work, and backups can retreive consistan=
cy (integrity).

does i miss something to do during all this actions ?

thank you in advance for your help
nicolas