Thanks to this thread, I got this working too. And thanks Lucho for that little trick - the # was driving me nuts!
My question is how do I modify the code to have mutliple links on a page (non marketo landing page). I have a page with the same event in different cities, on different dates. I want the user to click on the register button and have the form pop up for that city/date.
I've tried changing the ID like so (see bold) but it doesn't work. When i click, nothing happens.
<!-- NOVEMBER 12 EVENT -->
Having gotten this to work, I tried enabling the Social Form Fill. After clicking one of the three social buttons to do the autofill, a popup comes up that seems to connect to do the autofill but fails. You end up with the popup social fill being redirected to the home page and the lightbox form is not filled out. Is anyone else getting this issue?