Comment 3 for bug 150474

Gateway M-6319 has similar problem. Brightness doesn't work by either function keys nor brightness applet.
The function keys works following hacks on /etc/apci/video_brightnessup.sh and /etc/acpi/video_brightnessdown.sh as described on following forum threads:
http://ubuntuforums.org/showthread.php?t=767374
http://ubuntuforums.org/showthread.php?t=673946

But applet still doesn't work. I think whatever is called by acpi_fakekey 224 and 225 is not working correctly.

$ sudo dmidecode -s system-manufacturer
Gateway
$ sudo dmidecode -s system-version
3409361R
$ sudo dmidecode -s system-product-name
M-6319

xev output for function keys brightness up (key code 212) and down (101):

KeyPress event, serial 30, synthetic NO, window 0x3400001,
    root 0x59, subw 0x0, time 2511327, (731,745), root:(736,796),
    state 0x0, keycode 212 (keysym 0x0, NoSymbol), same_screen YES,
    XLookupString gives 0 bytes:
    XmbLookupString gives 0 bytes:
    XFilterEvent returns: False

KeyRelease event, serial 30, synthetic NO, window 0x3400001,
    root 0x59, subw 0x0, time 2511327, (731,745), root:(736,796),
    state 0x0, keycode 212 (keysym 0x0, NoSymbol), same_screen YES,
    XLookupString gives 0 bytes:
    XFilterEvent returns: False

KeyPress event, serial 30, synthetic NO, window 0x3400001,
    root 0x59, subw 0x0, time 2513724, (731,745), root:(736,796),
    state 0x0, keycode 101 (keysym 0x0, NoSymbol), same_screen YES,
    XLookupString gives 0 bytes:
    XmbLookupString gives 0 bytes:
    XFilterEvent returns: False

KeyRelease event, serial 30, synthetic NO, window 0x3400001,
    root 0x59, subw 0x0, time 2513724, (731,745), root:(736,796),
    state 0x0, keycode 101 (keysym 0x0, NoSymbol), same_screen YES,
    XLookupString gives 0 bytes:
    XFilterEvent returns: False