Ubuntu – 3 monitors with 2 video cards not working

I'm trying to get ubuntu working w/ 3 monitors. I have been given 2 video cards

lspci | grep VGA

20:01:00.0 VGA compatible controller: ATI Technologies Inc RV620 LE [Radeon HD 3450]
25:05:00.0 VGA compatible controller: nVidia Corporation NV44A [GeForce 6200] (rev a1)

I have two monitors plugged into my ATI card which is plugged into my primary PCIe slot, and one monitor plugged into my nVidia card

I have had it working correctly w/ two monitors (dvi|vga) plugged into the ATI card and the nVidia monitor blank. Now I have the nVidia monitor working (dvi) and one monitor from the ATI (vga) working, but I can't seem to get the last monitor on the ATI (dvi) to show anything. Both monitors plugged into the ATI cards show the boot screen, while the nVidia monitor is blank, and work up until the point you are presented w/ the login screen for Ubuntu, then the DVI monitor on the ATI card goes blank and the nVidia monitor turns on and works.

So now I have two screens working, one on each card. At first glance, it appears that my setup "wants" to work – looking how the wallpaper is rendered. My left screen is only half covered in wallpaper, while my middle monitor is fully covered, and it looks like the missing quarter of my wallpaper should render on the left half of my 3rd monitor on the right….not sure if that actually means anything.

Kinda like this, where X = wallpaper

 1   2   3
[ X][XX][X ]

Currently I'm seeing this error in my Xorg.0.log file, but I'm not sure where to go from here:

[    24.746] (EE) RADEON(2):  reusing fd for second head

Might I have something wrong w/ my xorg.conf or do I need to do something more to get this to work?

/etc/X11/xorg.conf

# nvidia-xconfig: X configuration file generated by nvidia-xconfig
# nvidia-xconfig:  version 270.29  (buildmeister@swio-display-x86-rhel47-02.nvid

Section "ServerLayout"
    Identifier     "Layout0"
    Screen      0  "Screen0" 0 0
    Screen      "Screen1" RightOf "Screen0"
    Screen      "Screen2" RightOf "Screen1"
    InputDevice    "Keyboard0" "CoreKeyboard"
    InputDevice    "Mouse0" "CorePointer"
EndSection

Section "Module"
    Load    "dbe"       # Double-buffering
    Load    "GLcore"    # OpenGL support
    # Load  "dri"       # Direct rednering infrastructure
    Load    "glx"       # OpenGL X protocol interface
    Load    "extmod"    # Misc. required extensions
    # Load  "v4l"       # Video4Linux
    Load    "record"    # X event recorder
    Load    "freetype"  # TrueType font handler
    Load    "type1"     # Adobe Type 1 font handler
EndSection

Section "ServerFlags"
    Option "Xinerama" "true"
EndSection

Section "Files"
EndSection

Section "InputDevice"
    # generated from default
    Identifier     "Mouse0"
    Driver         "mouse"
    Option         "Protocol" "auto"
    Option         "Device" "/dev/psaux"
    Option         "Emulate3Buttons" "no"
    Option         "ZAxisMapping" "4 5"
EndSection

Section "InputDevice"
    # generated from default
    Identifier     "Keyboard0"
    Driver         "kbd"
EndSection

Section "Monitor"
    Identifier     "Dell0"
    VendorName     "Unknown"
    ModelName      "Unknown"
    HorizSync       30.0 - 81.0
    VertRefresh     56.0 - 76.0
        Option         "DPMS"
EndSection

Section "Monitor"
    Identifier     "Dell1"
    VendorName     "Unknown"
    ModelName      "Unknown"
    HorizSync       30.0 - 81.0
    VertRefresh     56.0 - 76.0
    Option         "DPMS"
EndSectiSection "Monitor"
    Identifier     "Dell2"
    VendorName     "Unknown"
    ModelName      "Unknown"
    HorizSync       30.0 - 81.0
    VertRefresh     56.0 - 76.0
    Option         "DPMS"
EndSection

Section "Device"
    Identifier  "RD3450"
    Driver      "radeon"
    BusId       "PCI:01:00:0"
    Screen      0
EndSection

Section "Device"
    Identifier  "RD34501"
    Driver      "radeon"
    BusId       "PCI:01:00:0"
    Screen      1
EndSection

Section "Device"
    Identifier     "GF6200"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
    BusId          "PCI:05:00:0"
EndSection

Section "Screen"
    Identifier     "Screen0"
    Device         "GF6200"
    Monitor        "Dell0"
    DefaultDepth    24
    SubSection     "Display"
        Depth       24
    EndSubSection
EndSection

Section "Screen"
    Identifier     "Screen1"
    Device         "RD3450"
    Monitor        "Dell1"
    DefaultDepth    24
    SubSection     "Display"
        Depth       24
    EndSubSection
EndSection

Section "Screen"
    Identifier     "Screen2"
    Device         "RD34501"
    Monitor        "Dell2"
    DefaultDepth    24
    SubSection     "Display"
        Depth       24
    EndSubSection
EndSection

Section "DRI"
    Mode    0666
EndSection