Peter,
Go to the gallery, open the pic, right click on it, select and copy the text in the field Location, click in the Go Advanced tab when replying a thread, paste the text you've just copyed, select it again, and, finaly, click on the icon in the text window you are typing your message (and which is now set to Advance) that looks like a yellow square, with a mountain, and when hovered over with your mouse arrow, reads :Insert Image.
hope this helps, atleast that's how I do it...
Nenad