When using the option “Backup Database as SQL Dump”, the CREATE TABLE statements are exported in alphabetical order. If there are foreign keys on those tables, this will most likely cause problems when trying to execute the generated script.
For example, I have two tables “mail” (storing data about an email to be sent) and “attachments” (attachments for mails in the “mail” table). The “attachments” table has a foreign key referring to an entry in the “mail” table. Using “Backup Table…”, due to the alphabetical ordering, the statement “CREATE TABLE `attachments`…” appears before “CREATE TABLE `mail`…”, so the first statement fails because the second would have been to be executed before.