Hmm, that all looks ok..
Then I can only guess that FAA are maybe doing something.
Normally, you only get that when you try to access a https url when they dont have the correct certificate in place (which is the problem with AW sites because it has no HTTPS cert.)
But all your links look like they are fine.
Sorry, cant help more than that.
If its still doing it, try to see if it has changed the link to https when it happens again, I guess it could also be Tumblr doing something weird with links also...