Version: (using Devel) Installed from: Compiled sources When trying to reply to a message that contained an attachment the message "The message you have composed seems to refer to an attached file but you have not attached anything. Do you want to attach a file to your message?" appears. The given options are to attach a file, send as is or cancel. "Send as Is" and "Cancel" both result in a return to the message editor but don't send the message. I would expect the "Send as Is" to simply send the message.
I just checked this with kmail 1.11.1 When I reply to a message with an attachment, the "Do you want to attach a file?"-dialog isn't shown. If I create a message, be it a reply or a new one, and use the "attachment" keyword, the mentioned dialog shows correctly. If I choose "Send as is" it is sent without problems. So I assume this has been fixed.
Fully agree with Dominik