That seems to have done something - I have to confess I'm unsure what. However, it came back with:
Query Results:
SET @t4=0;
SELECT (@t4:=configuration_group_id) as t4 FROM zen_configuration_group WHERE configuration_group_title= 'Zen Lightbox';
DELETE FROM zen_configuration WHERE configuration_group_id = @t4;
DELETE FROM zen_configuration_group WHERE configuration_group_id = @t4;

Can you help me understand what that has done?

​Thank you so much for the reply!