Shouldn't the toons title be 'Darth' and not 'Lord'? As you have just earned the 'Darth' title and that ranking is considered to be a pretty big deal based on the story lines. Moreover, shouldn't NPC's now be calling you 'Darth' and the 'Lord' more of a secondary with NPC's who already know you?
I've always been a little confused with how titles work so maybe I'm missing something. Like I said it just seems to me that you should be called by your highest title?