Are you saying that the forum software is doing this?
I think so. When I look at the image in the post in Firefox and IE8, it appears to have been resized to fit in the post. If you follow my link to the image on one of my web pages it shows up as the full sized image. I know this used to be the way the image showed up in the old forum software.
Personally, for panos I like to see the full sized image and use the scroll bar to pan it. I think a pano resized down to post size loses its impact.