Sorry, I must have missed this because it wasn't in the dialog extension forum.
I see you're using Stencyl b8470. Which version of the Dialog Extension are you using (..unfortunately I haven't got a good setup for version numbers yet, so if you just know which download you used and around when you got it)?
Or better yet, if you could download the latest nightly build of the extension and then let me know if the bug persists, that would be great.