Jimlock, I am aware of the date ranges you are posting. What I am saying is that they do not matter. By the rules, Disciple of Dispater works despite the change in wording of Improved Critcial due to a case of specific vs general.
You appear to be arguing against this based on dates with the implication that it was not the intent of the designers that Disciple of Dispater continue working like that, at which point I would like to remind you that unless your name is Sean K. Reynolds, Monte Cooke, or another WotC/TSR employee, you have no idea of their intentions.