HPScanner get's cerated with weird permissions (expected ACL to contain perms for "lpadmin" group)

[Muelli]

Binary package hint: udev

When I plugin a HP Printer/Scanner via USB, the device node /dev/bus/usb/003/002 get's created like this:
$ getfacl /dev/bus/usb/003/002
getfacl: Removing leading '/' from absolute path names
# file: dev/bus/usb/003/002
# owner: root
# group: lp
user::rw-
user:gdm:rw-
group::rw-
mask::rw-
other::r--
$

The user, however, is not in the "lp" group, but rather in the "lpadmin" group. Hence it is not possible to use, say, "scanimage", because it can't use that above mentionend node properly. I would have expected that "lpadmin" is allowed to access that device node. However, there is no ACL entry for that.