Google PlusOne button not displaying

I was having an issue on our mobile site with the Google PlusOne button not displaying. When the HTML was generated the iframe had a height of zero. I have no idea why this was happening. Anybody have any clues please let me know.

Anyway to fix it I placed this CSS in my code which resolved it:

#___plusone_0 iframe {
height: 25px !important;
left: 0 !important;
top: 0 !important;
position: static
}