Well, now you've made me feel as though I've wasted my time with this... but I did figure out how to autocrop with GhostScript and pdfmanipulate with Windows. I posted the directions
in the other thread.
So it's -m3 that doesn't rotate it? Sorry, I thought it was both -m2 and -m3. I really should know, since I wrote a GUI for soPDF! But I haven't used it for months...