Form#serializeElements options.submit doesn't work with multiple buttons with same name
As mentioned in a couple of tickets the Form.serializeElements options.submit does not work on elements with the same name. We should probably check based on id first then fallback on name (my have some IE issues).
As Anthoney Hildoer pointed out there may be some solutions when the element is clicked but since Form.serialize may be called anytime and not just in an event handler, trying to figure out which element is clicked via event inspection may not be practical (event.explicitOriginalTarget for Mozilla browsers or document.activeElement for IE).
for some more background on this please read the related ticket:
We should also be checking inputs with a type of "image" because those act like submit buttons.