the only possible reason I could think of is that the database wasn't updated with new needed settings fields.
what you can try to do first is run the installer from step 5 again, this time you should see an error message instead of success, if you see success, then run it again to make sure. (error message is what we are looking for).
if that didn't help, then try update database manually via phpmyadmin by executing this query:
INSERT INTO 4images_settings (setting_name, setting_value) VALUES ('auto_image', '0');
INSERT INTO 4images_settings (setting_name, setting_value) VALUES ('auto_image_quality', '85');