Unfortunately you have to do a manual work around currently to inline an attached image.
What you do is go through the process of attaching an image, use the post preview option to see how your post will look. Right click and "copy the Link location", go to the edit box and create a "img" tag filled with the copied links location. You can then preview again to see the image inline.
..which appears to be visible only when logged in
post # 258 when logged out....

post # 258 when logged in....

the image is stored at.....sciforums.com/attachment.php?attachmentid=5700&d=1344440960