Same problem for me.Like I said, all images attached to posts are not displaying for me. Firefox, Chrome, logged in or not. This topic has an image attached to the second post; I cannot see that. I get the forbidden error message when I do try to click on the blank spot where the thumbnail ought to be.
I haven't seen anyone else state they also have seen this problem on this forum. But it happens to me on multiple machines, different browsers, not logged in or logged in, coming in from a variety of IP addresses. I'm curious to know if others are having the same problem.
Spurious cookies perhaps? I will clear them and see what happens. EDIT: cleared all cookies related to the combine forum. No change.