Originally Posted by secipolla
...the forum can't handle a thumbnail image that redirects to a url of the big image.
I can't authoritatively address the exact technical issue of why the image displayed by the IMG tags between the URL tags does not link to the big image while simple text between the URL tags does...
Your big image
For that, I will yield to those with the knowledge. But for now, what about doing the task this way?...
Isn't that the effect you want? I downloaded your big image, uploaded it as an attachment to this post, and inserted it where I wanted the thumbnail to go. It links to and displays the big image.