Warning!Zenphoto attempts to make log files accessable by owner only (permissions = 0600). This attempt has failed. The log file permissions are 0644 which may allow unauthorized access.
You should manually set the permissions, use .htaccess to prevent access to the folder, or fix the problem that caused Zenphoto not to be able to set the permissions in the first place.
I presume you have a hosted service. Talk with your support people. Tell them that you need the Web applications to be able to change permissions on files that they have created.