Can you put it up live somewhere that I can get FTP access? You could probably get around it by updating the MySQL setting sql_mode=only_full_group_by and turning that off, but I'd probably rather update the SQL statement to work with that setting turned on. If you send me FTP access, then I'll try logging in and get this fixed for you.
I'll need the url and login information you are using to be able to reproduce the issue as well.