Prb installation scanner

Bonjour,
Je viens d'installer mandiva 2008 et j'ai connecté mon scaner acer 620u.
j'ai suivi les instruction sur le théme [Linux] Installation d'un scanner USB sous Mandrake 10.1 de ce site.
Voici ce que m'indique la fenêtre du terminal

sane-find-scanner

# sane-find-scanner will now attempt to detect your scanner. If the
# result is different from what you expected, first make sure your
# scanner is powered up and properly connected to your computer.

# No SCSI scanners found. If you expected something different, make sure that
# you have loaded a kernel SCSI driver for your SCSI adapter.

# No USB scanners found. If you expected something different, make sure that
# you have loaded a kernel driver for your USB host controller and have setup
# the USB system correctly. See man sane-usb for details.

# Not checking for parallel port scanners.

# Most Scanners connected to the parallel port or other proprietary ports
# can't be detected by this program.

# You may want to run this program as root to find all devices. Once you
# found the scanner devices, be sure to adjust access permissions as
# necessary.
[lulu@bol62-1-88-160-53-137 ~]$ sane-usb
bash: sane-usb: command not found
Si quelqu'un peut m'aidé pour régler ce prb ce serai bien car j'ai un autre prb avec mon imprimante epson stylus color 640.
Mais je veux trouver une solution pour mon scan tout d'abord.
Merci pour votre aide