Looks like two drivers were fighting for the interface and thus the firmware upload fails. Here is what worked for me: echo 'blacklist usblp' > /etc/modprobe.d/delian-cups-fix.conf rmmod usblp /etc/init.d/cups restart Looks like the usblp blacklisting was part of cups package somewhere in the 1.4 version but later it was decided that it was no longer necessary. Apparently it is, or a different fix should be applied. Cheers -- Delian