Background Polyfill conflict with selectivizr.js

[ZCweb]

The polyfill works great. However when I use selectivizr,js the polyfill stops working. You see the image not scaling to contain the div. I need selectivizr because I use pseudo elements. But I would love to have this polyfill work. It sometimes on refresh seems to work for a micro second, then back to not behaving correctly. Please help. Thanks.