I've tried two different sql statement for add-on mods. They both fail in the same way.

This is the error:
9 statements processed.
ERROR: Cannot insert configuration_key "" because it already exists
Note: 1 statements ignored. See "upgrade_exceptions" table for additional details.

These are the SQL statements:
Code:
# remove Quick Updates setting 
#

#SELECT @quick_updates_id:=configuration_group_id
#FROM configuration_group WHERE configuration_group_title="Quick Updates";
#DELETE FROM configuration WHERE configuration_group_id=@quick_updates_id;
#DELETE FROM configuration_group WHERE configuration_group_id=@quick_updates_id;


SET @t4=0;
SELECT (@t4:=configuration_group_id) as t4 
FROM configuration_group
WHERE configuration_group_title= 'Quick Updates';
DELETE FROM configuration WHERE configuration_group_id = @t4;
DELETE FROM configuration_group WHERE configuration_group_id = @t4;

INSERT INTO configuration_group VALUES ('', 'Quick Updates', 'Set Quick Updates Options', '1', '1');
UPDATE configuration_group SET sort_order = last_insert_id() WHERE configuration_group_id = last_insert_id();

SET @t4=0;
SELECT (@t4:=configuration_group_id) as t4 
FROM configuration_group
WHERE configuration_group_title= 'Quick Updates';

INSERT INTO configuration (configuration_id, configuration_title, configuration_key, configuration_value, configuration_description, configuration_group_id, sort_order, last_modified, date_added, use_function, set_function) VALUES
('', 'Display the ID.', 'QUICKUPDATES_DISPLAY_ID', 'true', 'Enable/Disable the products id displaying', @t4, 1, NOW(), NOW(), NULL, 'zen_cfg_select_option(array(''true'', ''false''),'),
('', 'Display the thumbnail.', 'QUICKUPDATES_DISPLAY_THUMBNAIL', 'true', 'Enable/Disable the products thumbnail displaying', @t4, 2, NOW(), NOW(), NULL, 'zen_cfg_select_option(array(''true'', ''false''),'),
('', 'Modify the model.', 'QUICKUPDATES_MODIFY_MODEL', 'true', 'Enable/Disable the products model displaying and modification', @t4, 3, NOW(), NOW(), NULL, 'zen_cfg_select_option(array(''true'', ''false''),'),
('', 'Modify the name.', 'QUICKUPDATES_MODIFY_NAME', 'true', 'Enable/Disable the products name editing', @t4, 4, NOW(), NOW(), NULL, 'zen_cfg_select_option(array(''true'', ''false''),'),
('', 'Modify the Description.', 'QUICKUPDATES_MODIFY_DESCRIPTION', 'true', 'Enable/Disable the displaying and modification of products description', @t4, 5, NOW(), NOW(), NULL, 'zen_cfg_select_option(array(''true'', ''false''),'),
('', 'Modify the status of the products.', 'QUICKUPDATES_MODIFY_STATUS', 'true', 'Allow/Disallow the Status displaying and modification', @t4, 6, NOW(), NOW(), NULL, 'zen_cfg_select_option(array(''true'', ''false''),'),
('', 'Modify the weight of the products.', 'QUICKUPDATES_MODIFY_WEIGHT', 'true', 'Allow/Disallow the Weight displaying and modification?', @t4, 7, NOW(), NOW(), NULL, 'zen_cfg_select_option(array(''true'', ''false''),'),
('', 'Modify the quantity of the products.', 'QUICKUPDATES_MODIFY_QUANTITY', 'true', 'Allow/Disallow the quantity displaying and modification', @t4, 8, NOW(), NOW(), NULL, 'zen_cfg_select_option(array(''true'', ''false''),'),
('', 'Modify the manufacturer of the products.', 'QUICKUPDATES_MODIFY_MANUFACTURER', 'false', 'Allow/Disallow the Manufacturer displaying and modification', @t4, 9, NOW(), NOW(), NULL, 'zen_cfg_select_option(array(''true'', ''false''),'),
('', 'Modify the class of tax of the products.', 'QUICKUPDATES_MODIFY_TAX', 'false', 'Allow/Disallow the Class of tax displaying and modification', @t4, 10, NOW(), NOW(), NULL, 'zen_cfg_select_option(array(''true'', ''false''),'),
('', 'Modify the category.', 'QUICKUPDATES_MODIFY_CATEGORY', 'true', 'Enable/Disable the products category modify', @t4, 11, NOW(), NOW(), NULL, 'zen_cfg_select_option(array(''true'', ''false''),'),
('', 'Display price with all included of tax.', 'QUICKUPDATES_DISPLAY_TVA_OVER', 'true', 'Enable/Disable the displaying of the Price with all tax included when your mouse is over a product', @t4, 20, NOW(), NOW(), NULL, 'zen_cfg_select_option(array(''true'', ''false''),'),
('', 'Display the link towards the products information page.', 'QUICKUPDATES_DISPLAY_PREVIEW', 'false', 'Enable/Disable the display of the link towards the products information page ', @t4, 30, NOW(), NOW(), NULL, 'zen_cfg_select_option(array(''true'', ''false''),'),
('', 'Display the link towards the page where you will be able to edit the product.', 'QUICKUPDATES_DISPLAY_EDIT', 'true', 'Enable/Disable the display of the link towards the page where you will be able to edit the product', @t4, 31, NOW(), NOW(), NULL, 'zen_cfg_select_option(array(''true'', ''false''),'),
('', 'Activate or desactivate the commercial margin.', 'QUICKUPDATES_ACTIVATE_COMMERCIAL_MARGIN', 'true', 'Do you want that the commercial margin be activate or not ?', @t4, 40, NOW(), NOW(), NULL, 'zen_cfg_select_option(array(''true'', ''false''),'),
('', 'Modify the sort order.', 'QUICKUPDATES_MODIFY_SORT_ORDER', 'true', 'Enable/Disable the products sort order modify', @t4, 11, NOW(), NOW(), NULL, 'zen_cfg_select_option(array(''true'', ''false''),'),
('', 'Use popup edit.', 'QUICKUPDATES_MODIFY_DESCRIPTION_POPUP', 'true', 'Enable/Disable using popup edit link to description editing', @t4, 11, NOW(), NOW(), NULL, 'zen_cfg_select_option(array(''true'', ''false''),');
There is nothing in the update_exceptions table