I'm not sure about this... I want to upload them in movie order... But it will take a long time :)

It might get complicated for you if you start doing them in order, as that's not what you're used to. It also might look weird if the older screenshots are uploaded randomly and the new ones are in order. The screenshots always seem to be properly keyworded and that's the important thing - even if they're not in a proper order, at least with keywords people will know where to look! :)