I've had similar experiences. Switching to Safari seems to help when this happen. I don't expect they'll be doing this on purpose. It could be that the encoded

I've had similar experiences. Switching to Safari seems to help when this happen. I don't expect they'll be doing this on purpose. It could be that the encoded video block required by Firefox and not used that much, as such the cache hit rates are bad requiring trips back to an overloaded origin server.