Weird. It's working for me now. I think it was too many suspend/resumes, or maybe some bitchiness from the printer itself (going into cycles of downloading firmware endlessly).
On the way through, I noticed Adobe Acrobloat does have a booklet printing option. psbook does similarly and processes pdfs also. There is also psbook. With a 4 page pdf, I was doing this
Code:
bash-4.2$ pdfseparate file.pdf test%d.pdf
bash-4.2$ ls test*
test1.pdf test2.pdf test3.pdf test4.pdf
bash-4.2$ pdfunite test4.pdf test1.pdf front.pdf
bash-4.2$ pdfunite test2.pdf test3.pdf rear.pdf
bash-4.2$ lp -o media=a4 -o landscape -o number-up=2 front.pdf
bash-4.2$ lp -o media=a4 -o landscape -o number-up=2 rear.pdf
But I was getting stuck on the pdfunite stage. Thx again