Hello and thank you for developping PDF-Shuffler! :)
It seems that I'm not able to launch pdf-shuffler with the latest revision because pdfshuffler.ui file is not found.
This is why I'm proposing this tiny patch in order to fix this bug:
* setup.py: install pdfshuffler in share/pdfshuffler (e.g.: /usr/share/pdfshuffler/pdfshuffler.ui)
* pdfshuffler.py: look in the right directory in (/usr/local/share/pdfshuffler/pdfshuffler.ui) (now the file is detected if it has been installed in /usr/share or in /usr/local/share but it is still not found if the user changes the prefix of the installation (except if you've forgiven this possibility somewhere, sorry if it's the case!))
I hope this patch can be helpful :)