nemethand, how do you know you have more objectives than you can currently hold? All extra objectives appear either through historical event or through 1% possibility each turn by the new objectives event. Did you get messages for more objectives when that F10 screen was already populated full?
Jim-NC, your case is probably WAD. It's unfortunate, but you probably don't have enough Generals in the correct appearance date. You will have to wait for the new DateIn and then they will spawn automatically.