It's easy once you know how to do it though.
For example, go to your "
project Board Chow" post. Hover over the attachment link and right-click it. Select "Copy link location" or whatever your browser has to copy a link instead of just following it.
Now go to the thread you want to reply in and start writing your reply up to the point where you want to insert your picture.
In the toolbar at the top of the message editor is an icon to insert pictures. It sits right beneath the undo button and looks like a yellow picture with two mountains and a litte sun in it.
Click it and a window will pop up. Select everything in the text box, right click the selected text and choose Paste. Now click ok, and there should now be something like this in your text:
[IMG]http://geekhack.org/attachment.php?attachmentid=3927&d=1250843768[IMG]
When you now click the "Preview Post" button, your image is included in your text.
Also note that you can also include images when you haven't posted your message yet. If you attached any files using the "Manage attachments" tool, you'll see that the attached files are shown beneath the button. You can copy these links and add them to your post as explained above.