Full Mac Backup doesn't include all files

I'm running Backup Exec 2010 R2 and the Mac client is an old 10.4. The selection includes all files and the user used is ROOT. The File System has 598,601 files. The Backup ends successfully with 3 files excluded (2 are corrupted and 1 is locked). The Backup reports 597,563 files. There are about 1000 files missing. Why?