I think @skreza got it right.

skreza (57)
it happens when the network is slow.. how do I explain this.. ok logout and open any post while you are logged off.. you will see every post will show that below.. now login back and you won't see that message.. but sometimes when you are logged in but the page is still loading that message will show up, specially when the network is slow and takes time to complete the loading..

Thanks!