Is there such a thing as a pristine manuscript? I've come to the conclusion the answer is no.
Different font, different spacing, print it out to edit on hard copy, leave for a few days to have fresh eyes - it doesn't matter if I do one, or all of them, typos and grammatical errors breed as soon as I hit 'save'.
At least I don't have the urge to throw my laptop out of the window anymore. I just sigh and correct, sigh and correct, sigh and correct again.