I agree this is permissions, but I ran into this same thing using saned to set up a networked scanner. I had to modify permissions accordingly. Some devices, for whatever reason, are by default readable/writable only by root. I think that regardless of his configuration he will have to modify the permissions on the device.
Jason
This is probably a result of your scanner device is not readable by other users than root. If you no what your scanner device is called you could change the permissions for the device so that all users can access it.
Another, better, solution would be to set it up as a networked scanner by using saned. The procedure is well described in the saned man page. Follow that example and don't forget to restart your xinetd to make it work. Also make sure that the line "net" in /etc/sane.d/dll.conf is not commented out. Add localhost to /etc/sane.d/net.conf That way your scanner device could be owned by one saned user, and the access to it could be controlled by editing the file /etc/sane.d/saned.users (see the saned man page).