Found same issue with Java-Uploader image too under Admin-Utilities

Can't reproduce - could you provide a link to where you see the error?

I went to take SS for you and realized I was in v8 Addons. I checked v9 Addons and it is fine there. As stated before both GESHI and JAVA uploader do this. Others work but I am sure there are more that might not.
oh here is link to Java uploader

http://compo.sr/site/downloads/entry/addons/Composr-8-0/admin-utilities_7/java-uploader-ftp_6.htm

and Geshi

http://compo.sr/site/downloads/entry/addons/Composr-8-0/information-display_7/geshi_7.htm

Still can't see any issue - the images show for me, in multiple browsers, as logged in as guest, after doing a hard cache-clear.

I tried in other browser and I still get issue. I am talking when you click on the image to open overlay the overlays just hangs and if you click view full image it goes to a 404 I am attaching a SS to view

(Click to enlarge)

I am logged in not as guest.

Thanks