Thanks Matt,

I finally worked out what was messing things up. I have a bunch of article styles that set title colour, background color and button colours for each article - kind of like a 'theme' for each article that I interchange.

The style I was using for the peelBackHotspot had the following line in it:
button:hover {background-color: #000 !important; transition: all 0.5s; -webkit-transition: all 0.5s; -moz-transition: all 0.5s;}

The transition part was completely conflicting with the code for the component peeling back/forth somehow. No idea why. 2 types of transitions being called at the same time maybe? Anyways, ditched the CSS and it's perfect!

Thanks again