your mistake i'm afraid, not Carib's, you are starting your simulation with the "Start draping from zero pose" option checked, in the simulation options, you need to uncheck this to start the simulation calculations from the adjusted pose, and not the "zeroed pose"

with it checked it is gonna alter the V3 pose back to zero, which is how it was before you adjusted the pose to fit inside the gown, you should always adjust the figure pose to fit the gown as you do not know whether the cloth was actually made for the default vicky or one that had had a morph already applied to it.

also worth checking (as i can't see your results) that you have the cloth colliding against V3 figure ( that's where you will see the checked "start draping from zero pose"option) and maybe the ground (if nessersary) a good tip is to hide the hair (if already placed on figure) before selecting the "collide against" options, as with it hidden you get into less trouble during the simulation calculations.

hope that fixes it for ya.