I think you need to add a Nautilus action
, in the Nautilus-Actions Configuration. From that topic I'm assuming this was installed by default in older versions, but not anymore. Also make sure to have enabled the mintUpload background service in the Startup Applications.
ThistleWeb, a forum member (who is knowledgeable about such things
), has a screencast on using mintUpload: http://thistleweb.co.uk/screencast/linux/mintupload