Error when copying to subdirectories

[nomis56]

Hi

I have a user who can see the contents of all his folders via ftp but can only copy across to the top level. When he tries to move files to a subfolder the error is
550 permission denied
critical file transfer error


I have looked at 2 other users on my system (different domains) who can copy to all their sub-folders.

I've looked in sentora_core&table=x_ftpaccounts and sentora_proftpd&table=ftpuser but cannot see any differences to the settings between the 3 users

Is there anywhere else that I should be looking?

Thanks

[TGates]

Login through SSH and make sure the user's file and folder permissions are owned by www-data:www-data and 755