OK. So I've been investigating a bit. The apropriate udev scripts are present in /etc/udev/rules.d/45-libnjb.rules.
These correctly set the permissions on /dev/bus/usb/00x/00y to root:plugdev and 0660 and my user is in the group plugdev. I can't seem to repeat the problem after having used the old hotplug scripts, even though I have removed them now. But the first time I plugged the zen in, it gave this error message. -- hotplug scripts are not installed https://launchpad.net/bugs/1497 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs