Microsoft Outlook: Attachment field does not appear in header

Being a heavy user of Outlook 2007, I found it really annoying when writing an email and adding an attachment when sometimes it would appear in the body of the email, rather than where it should be; on the attachments bar at the header of the message:


I thought it was a bug so I kept restarting Outlook but it had no effect. When I created a new message and added an attachment, it would behave the way I wanted.

Then I figured out that it's something really straightforward. If the message is in Rich Text Format the attachments will appear in the body of the message (which looks messy), but if you change it back to HTML or Plain Text format they will go back to the attachment bar in the header - where they should be!

Simples!