FYI see the "sane to work with USB 3.0" mail thread on http://lists.alioth.debian.org/pipermail/sane-devel/2014-November/thread.html http://lists.alioth.debian.org/pipermail/sane-devel/2014-December/thread.html in particular http://lists.alioth.debian.org/pipermail/sane-devel/2014-November/032853.html and the "Scanner failure when connected via USB3" mail thread on http://lists.alioth.debian.org/pipermail/sane-devel/2015-February/thread.html