(could not update the last post so ...)
UPDATE: So getting closer to the original text form of fileId="52" thumb="y" rel="boxg" width="66%" that stopped working, I see that a variation to my update of before is src="dl16" thumb="zoombox" width="100px". When clicking on the thumbnail, I get a blank popup as before but now also get the file downloaded and popped-up in a local screen that displays the image (if the browser and device is setup to allow such action). Overall, it seems a pop-up or mouseover with a fileid= reference stopped working. Changing it to src="dlnnn" seems to resolve some of the problems except the thumb with pop-up function still does not work as before. I am still not able to recreate on your test site as the virtual installation does not install correctly (configuration error).