I agree the crontab mess has nothing to do with the password change dialog, but with the cron thing is definitely something wrong. I deleted the content of crontab but when I click save under konfig -> backup all the things reappear in crontab inclusive the error message “can’t install cron: bad day-of-week”.
UPDATE: It’s not only the backup-dialog it’s also with the register user and probably some more (I did not test more function yet).