I have an ATI Radeon 9000 Pro and I used the thread titled "ATI Radeon 9000 Pro Dual Display Problems" to get my dual display up and running:
Although, I'm having trouble setting up the exact dual display I want. Here is my situation:

I have 2 CRT monitors: One is an Envision 775e and the other is a Viewsonic E771. On my desk the Envision is placed on the left and the Viewsonic on the right. So naturally, I want the Envision monitor to be my "main" display and the Viewsonic to be the "extended desktop."

Right now I have the "main" display as the Viewsonic monitor and the "extended desktop" is the Envision monitor, which is placed RightOf the Viewsonic. Of course I could change that command to LeftOf but that still doesn't get me the "main" display where I want it.

Now, I know what you're thinking... just switch the monitor cables plugged into the video card, right? Well, that's where I run into my problems. When I do that, the displays revert to "Clone" and not "DualHead."

So does anybody know what I am doing wrong?
Any help is greatly appreciated!!

Below is a copy of my XF86Config file.

# XFree86 4 configuration created by C-Span


Section "Files"

# The location of the RGB database. Note, this is the name of the
# file minus the extension (like ".txt" or ".db"). There is normally
# no need to change the default.
# Multiple FontPath entries are allowed (they are concatenated together)
# By default, Red Hat 6.0 and later now use a font server independent of
# the X server to render fonts.
RgbPath "/usr/X11R6/lib/X11/rgb"
FontPath "/usr/X11R6/lib/X11/fonts/local/"
FontPath "/usr/X11R6/lib/X11/fonts/misc/"
FontPath "/usr/X11R6/lib/X11/fonts/75dpi/:unscaled/"

EndSection

Section "Module"
Load "GLcore"
#Load "dri"
Load "dbe"
Load "extmod"
Load "fbdevhw"
Load "glx"
Load "record"
Load "freetype"
Load "type1"
EndSection



Section "InputDevice"

# Option "AutoRepeat" "500 5"
# when using XQUEUE, comment out the above line, and uncomment the
# following line
# Option "Protocol" "Xqueue"
# Specify which keyboard LEDs can be user-controlled (eg, with xset(1))
# Option "Xleds" "1 2 3"
# To disable the XKEYBOARD extension, uncomment XkbDisable.
# Option "XkbDisable"
# To customise the XKB settings to suit your keyboard, modify the
# lines below (which are the defaults). For example, for a non-U.S.
# keyboard, you will probably want to use:
# Option "XkbModel" "pc102"
# If you have a US Microsoft Natural keyboard, you can use:
# Option "XkbModel" "microsoft"
#
# Then to change the language, change the Layout setting.
# For example, a german layout can be obtained with:
# Option "XkbLayout" "de"
# or:
# Option "XkbLayout" "de"
# Option "XkbVariant" "nodeadkeys"
#
# If you'd like to switch the positions of your capslock and
# control keys, use:
# Option "XkbOptions" "ctrl:nocaps"
# Option "XkbOptions" ""
#
Identifier "Keyboard0"
Driver "keyboard"
Option "XkbRules" "xfree86"
Option "XkbModel" "pc105"
Option "XkbLayout" "us"
#Option "XkbVariant" ""
EndSection

Section "InputDevice"
Identifier "Mouse0"
Driver "mouse"
Option "Protocol" "imps/2"
Option "Device" "/dev/input/mouse0"
Option "ZAxisMapping" "4 5"
Option "Emulate3Buttons" "no"
EndSection

Section "Monitor"
Identifier "Monitor0"
VendorName "Viewsonic"
ModelName "E771"
DisplaySize 340 270
HorizSync 30.0 - 70.0
VertRefresh 50.0 - 120.0
Option "dpms"
EndSection

Section "Monitor"
Identifier "Monitor1"
VendorName "Envision"
ModelName "775e"
DisplaySize 340 270
HorizSync 30.0 - 72.0
VertRefresh 50.0 - 160.0
Option "dpms"
EndSection

Section "Device"
Identifier "ATI Radeon 9000 Pro 0"
Driver "radeon"
VendorName "ATI Radeon 9000 Pro"
BoardName "ATI Radeon 9000 Pro"
BusID "PCI:3:0:0"
Screen 0
EndSection

Section "Device"
Identifier "ATI Radeon 9000 Pro 1"
Driver "radeon"
VendorName "ATI Radeon 9000 Pro"
BoardName "ATI Radeon 9000 Pro"
BusID "PCI:3:0:0"
Screen 1
EndSection

Section "Screen"
Identifier "Screen0"
Device "ATI Radeon 9000 Pro 0"
Monitor "Monitor0"
DefaultDepth 24
SubSection "Display"
Depth 24
Modes "1280x1024" "1024x768" "800x600" "640x480"
EndSubSection
EndSection

Section "Screen"
Identifier "Screen1"
Device "ATI Radeon 9000 Pro 1"
Monitor "Monitor1"
DefaultDepth 24
SubSection "Display"
Depth 24
Modes "1280x1024" "1024x768" "1024x768"
EndSubSection
EndSection


Section "ServerLayout"
Identifier "DualHead"
Screen "Screen0"
Screen "Screen1" RightOf "Screen0"
InputDevice "Mouse0" "CorePointer"
InputDevice "Keyboard0" "CoreKeyboard"
Option "Xinerama" "on"
EndSection

Tried initialising them the other way round?

Same Results... thanks though.