Backbone element.click() event not working in Selenium python

It is sometime rather frustrating when working with Selenium and WebDriver that your element is found but the click() action doesn't fire the event behind it!

Before you give up try seeing the suggestion from Selenium IDE. Sometime just a seemingly innocuous change will make it work. Like this example I resolved today:

FAILED:
driver.find_element_by_css_selector(".modal-footer button.btn-primary.btn").click()

WORKS:
driver.find_element_by_css_selector(".modal-footer > button.btn-primary.btn").click()

Both returned True on is_element_present but the first one did not fire event when clicked with click().