I have two scanners attached to my computer, a Brother MFC-8500 and an HP Photosmart C4210. I was using gscan2pdf with the HP and accidentally set it to scan "all" pages instead of just one from the flatbed. A known issue caused the scanner to continuously scan with no way of stopping it. I turned off the scanner, saved the document and the tried scanning a different document with the Brother scanner. Instead of the normal operation I usually get, I instead got "Unable to open device, Invalid Argument"

scanimage -L gives me:
Code:
WARNING: gnome-keyring:: couldn't connect to: /run/user/**********/pkcs11: No such file or directory
device `brother:bus4;dev1' is a Brother MFC-8500 USB scanner
device `hpaio:/usb/Photosmart_C4200_series?serial=CN7ACNF046055B' is a Hewlett-Packard Photosmart_C4200_series all-in-one
this does not seem to align with lsusb:
Code:
Bus 001 Device 011: ID 1a40:0101 Terminus Technology Inc. 4-Port HUB
Bus 001 Device 004: ID 0bc2:5071 Seagate RSS LLC 
Bus 004 Device 002: ID 2040:4903 Hauppauge HS PVR
Bus 004 Device 004: ID 04f9:0113 Brother Industries, Ltd MFC-8500
Bus 006 Device 002: ID 09da:0006 A4 Tech Co., Ltd Optical Mouse WOP-35 / Trust 450L Optical Mouse
Bus 006 Device 003: ID 046e:5542 Behavior Tech. Computer Corp. 
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 006 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 007 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 001 Device 012: ID 046d:c21d Logitech, Inc. F310 Gamepad [XInput Mode]
Bus 001 Device 013: ID 0409:005a NEC Corp. HighSpeed Hub
Bus 001 Device 014: ID 0c45:6340 Microdia 
Bus 001 Device 015: ID 03f0:5c11 Hewlett-Packard PhotoSmart C4200 Printer series
Bus 001 Device 016: ID 04e6:5116 SCM Microsystems, Inc. SCR331-LC1 / SCR3310 SmartCard Reader
uname -r
Code:
3.5.0-17-generic
lsb_release -a
Code:
LSB Version:    core-2.0-amd64:core-2.0-noarch:core-3.0-amd64:core-3.0-noarch:core-3.1-amd64:core-3.1-noarch:core-3.2-amd64:core-3.2-noarch:core-4.0-amd64:core-4.0-noarch
Distributor ID: Ubuntu
Description:    Ubuntu 12.10
Release:        12.10
Codename:       quantal
dpkg -l brscan
Code:
ii  brscan         0.2.4        amd64        Brother CUPS Printer Definitions
hours of searching have given lots of helpful suggestions including modifying /lib/udev/rules.d/40-libsane.rules and adding
Code:
# Brother scanners
ATTRS{idVendor}=="04f9", ENV{libsane_matched}="yes"
also copying brscandec, brcolm, and sane libraries from /usr/lib64 to /usr/lib. I had to do all thisto get it working the first time and that hasn't changed.

I uninstalled and re-installed sane and the brscan packages. I checked the Brother website for help. I also have done the obvious and rebooted.

So far nothing has managed to solve my problem, which has made a scanner that has been working great act like there is something wrong that it cant work. Any help would be appreciated.