When I post, my image data appears in-lined with the message, which seems to break after a while. I can see that other images in the forum are linked from photobucket, but when I paste the HTML into the forum reply, the HTML appears literally, rather than being interpreted as part of the post. Does anyone know how I can directly add HTML to my post, bypassing the WYSIWYG editor?

Not possible Dunno. You cannot paste HTML directly into the reply box.

You need to use an editor as I previously mentioned.

I don't know why you cannot drag the Image from Squarefree into reply box? It should work.