I already noted that as being a bug in the demo. I think it has something to do with a whole line being made up of displayable inserts instead of actual text and renpy not being able to figure out the proper width of things. My best solution right now is to just say to add the line breaks in manually for where you know they should be. You can use \n or the {para} tag used in the demo. I know it's annoying but been too busy with other things to really look into a serious fix to avoid it. Sorry about that.