Patrice, I'm not running any "new" ad blockers either. Nothing had changed when I started having the problem. To make it more "interesting"....I CAN see them with my iPod..using the same router/server. You would think that would mean that I could use Safari on my computer and see them then, right???? Nope...can't.
The same thing happened to me as someone above..I could see older pics and avatars until I cleared my cache..now, not even those.