Not sure if this is related...... I keep finding random photos in my user galery that other people have uploaded. When I find them I delete them. I think there is a glitch in the matrix that has something to do with duplicate file names.
It's really not consistent, with the same thread open in Firefox 18 and Chrome 24, some images are visible in one and not the other, and some are not visible in either. In one of my posts there are two images visible in Chrome and five visible in Firefox, and in that same thread in another post a photo is not visible in either browser. And further down in that same thread, of two images posted, one is visible in Chrome and the other image in Firefox.
There are no broken image symbols for the missing images either.
I tried changing one image from attached to embedded and it made no difference.
This might be related to the Forum Upgrade coming. Perhaps things are getting moved on the server and links are being changed temporarily or having a hard time parsing.
I also wonder if clearing your cookies and logging back in would help. Perhaps the cache is full or at limit.
I just looked at the same thread in IE8 and it is missing some images out of the same group. It is missing some very recent images and a few older images.
I'm having the same issues using Chrome and Firefox on Windows 7. I refuse to use IE. I'm also having the problem on my iPad. The problem varies from thread to thread, and from browser to browser.