Actually I've never used it myself until now. It's a little needed function in my eyes. I saw a post on
http://www.phpbb.com/community where somebody was asking to remove that button.
Ok. I'll try now.
Seems to work fine. I have the german language running as board language now. It says to the right of title "Entwurf laden" meaning in english about "load draft". Upon clicking that it places your post in the forum where you wanted to post it. Then you have the "Submit" button there as usual. If you can read this it worked!
