Thats how you are suppose to do it. An image is inserted at the current paragraph location, which is the first line unless you add a few paragraphs then insert the graphic. But it should still be inserted where the cursor is.
But if you fail to that, you can insert paragraphs at the end then select the graphic and drag downward to place it at a different paragraph.
Keep in mind that in the background the forum code for the text box is text only. It works that same as how html is. It uses tags for special features like images. And this is why graphics are anchored to paragraphs.
