Howard,Apparently it's something from XF in the latest update? XF 1.5 - Some users cannot see attachments when inserted into post
Other sites are reporting problems.
I've posted a support thread reporting this particular issue. In the meantime, there's not much I'm going to do on this... if it's an XF problem, I'm not going to spend time digging through their code to find an error.
It looks like one of the xenforo devs is looking for a link to a thread with an example this week. Obviously this thread has tons of examples. There's also a recent post from rhwestfall here AL63 how do they swim that has the problem. "thumb2" emote.