[TYPO3] Permission issues with Full Backup w4x_backup

[Magnus Wester]

Hi, I started using Typo3 just a few days ago. My installation runs on a 
  Linux server and I seem to have permission-related issues with the 
Full Backup extension.

When I go to the Backup tab, it says "The BACKUP tool will check whether 
nobody, which is the server's user name, has the appropriate permissions 
and ownerships to do the backup." Is this normal or is there a way to 
set a username/password for the backup program? I can't find it in the 
settings.

When I run a backup, I get an Operation log indicating permissions 
problems for files in the typo3conf, fileadmin and uploads folders. 
However, the permission is set to 777 for all these folders.

If I select "Proceed without permissions check." the backup runs fine - 
with the same warnings of course.

I have reset the Backup dir in the setings to typo3temp/w4x. Initially I 
set it to typo3temp/backup, but that definitely did not work. A backup 
file was created without errors, but it was unreadable.

Any suggestions?

Magnus