I have exactly the same problem as the original reporter, with an Epson RX620. It works fine as root, but fails as a non root user. Appropriate entries under /proc/bus/usb are only accessible to root.
Using sane-utils 1.0.19-1 from sid. Mike -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]