That's strange all right. When you have graphics turned off in your iHub settings you see "[Suppressed Chart Link]" in the top posts like you're supposed to, but not in the bottom posts.
It's something to do with the URLs the guy is posting. In the top set, the URLs all end with something like "&r=5529" but in the bottom set (where the link doesn't show up) the URLs all end in something like "&r=9402/chart]<br"
The guy may be doing something wrong during copy/paste