When configuring a web service to respond with multiple attachments as per article http://www-01.ibm.com/support/docview.wss?uid=swg21563035 there is no way to set the content type of the individual attachments. All attachments are set to be the value in the soa.properties property attachmentMimeType. If you have multiple attachments of different types the result is not correct.
As a workaround we were manually creating the mime header and setting the content type correctly there. However, since the introduction of 18.104.22.168 this no longer works and all attachments are application/octet-stream