Wintermute automaticaly scrolls to the Game.MainObject, wich is assigned to the actor
Game.MainObject = actor;
in "game.script" right before loading the first scene. Just delete that line and put it wherever you want it, or whenever, like after a Sleep(ms) in the "scene_ini.script" of your first scene. That is, if I understood you correctly.
Hope it helps.
EDIT: Oh, well, I supose
Scene.AutoScroll = false;
at the beginning of a scene and then return it to true would also work.