First of all, the link:

As you load the page (in Google Chrome) the browsers Refresh button starts flickering.
Here is a video I made, showing what I mean:

For troubleshooting purposes, I tried disable JavaScript in my browser. The problem disapears.

So... what script is causing this?
I first noticed the problem when i was messing around with the fancybox settings in theme.js, but it might not be related to that.