For the benefit of newcomers to this issue, let me try to distill the past history of testing that lead us to this point. Not all of these points have been established to the same level of proof.
-Standard test methodology has been as described below. Run for a bit just ending turn and note the number of provinces taken or sieges prosecuted if you had FOW off. Run the same campaign saving and loading every turn and watch things fail to be conquered and the AIs move defensively or aimlessly.
-Quicksaves, autosaves, and named saves have all been tested and found to display the same behavior.
-Loading from the manual interface and loading using continue campaign have been found to produce the same behavior.
-Loading every other turn has been found to catch the AIs in a loop of alternately laying siege on the turn not preceeded by a load and lifting siege on the turn preceeded by a load, indicating that the decisions produced after a load are materially different that normal even in very similar situations.
-Timing of the load within the player's turn if the player is active has been shown not to have an effect.
-Player inactivity with loading produces AI inactivity. Player inactivity without loading produces AI activity.
-Two loads per turn without player activity does not appear to affect the AI's pacifism after loading in my VERY limited test last night. The fact that Roguebolo loads multiple times during a turn and has yet to see a single AI siege lifted in his campaigns indicates that this one needs testing badly.
-AFAIK, RB is the only person who has experienced the bug in testing but not in campaign.

That is the body of fact as I see it. My understanding of the purpose of this thread is to gather statistical evidence of these facts instead of the semi-anecdotal evidence currently available. Hypotheses that can explain these observed facts are probably welcome as well (especially testable ones), although that is the moderator's call. Personally, I'd be particularly interested in anyone that can explain or duplicate RB's results. What makes him special that his AI's work?