Firefox and Android devices give a problem with the vimeo fix as it triggers the event immediately. Not on the next image.

I found that I could disable the fix, will have to retest if this works properly with Vimeo, but it could be that our new way of calculating 'top' no longer requires this fix?
Merge pull request #19 from rayburgemeestre/master

Firefox and Android devices give a problem with the vimeo fix as it trig...