Gah, sorry - somehow missed your previous post!
Those crontab outputs explain what is going on. The back.sh script is being run as user basil, whcih means that when it comes to copying the backup file to the target location you do not have the correct permissions to access the contents of the directory (it is rwx by root only).
So, what do we do? Hoping it is ONLY the directory permissions which are fouling things up we have a range of options which, in not particular order of 'good', include:
a) change ownership/permission on target directory.
b) have the back.sh script run by the root user
c) set up sudo to permit the file copy to be done by root
d) use setuid on the back.sh to have it run, effectively, as root
A lot of the answer will depend upon what else the Dropbox directory is for. If it's JUST for your backups for this then I'd be inclined to:
chown basil /root/Dropbox
chmod g+rwx /root/Dropbox
which will permit the basil user full access and thus allow the file operations being done and give root access via the group permissions (not that the root user really needs this).
Also, I'd be inclined to:
chown basil /home/xxxx/moo3/bin/back.sh
chmod u=rwx,g=rx,o= /home/xxxx/moo3/bin/back.sh
which will make things 'look' better, it just reinforces the point that the script is run (and owned) by the basil user.