Is 4chan doing something different with their javascript in the last few days?

It seems like everytime I load a page my browser (FF) will load partially and then lock up until all the image files are downloaded fully. On catolog mode it might lock up for 2-3 seconds. And I mean it locks up. I can't select a different tab or minimize firefox. It is completely unresponsive until the loading is finished.

This is new. Only been happening for a few days. Anyone know why or ways to work around it?