- The script is not executed by cron, whereas it is copied in /etc/cron.daily
First of all, check that the script is executable. To be sure, launch it manually in command line. If it's not executed, then chmod the script to 755.
example : # chmod 755 /etc/cron.daily/zyxBackup-0.2-81106
If you can execute the script manually, but if the script is still not executed by cron, then the problem can come from a known bug of cron. (See here, and here). This bug makes the scripts named with characters like "-" or "." silently not executed. Silently, because no error is reported in syslog.
To resolve this issue with zyxBackup, you simply have to rename the script to "zyxBackup".