[bglug] dual monitor

[renato daprà]

Ho collegato due monitor alla mio pc (Ubuntu Horay) con scheda video
dual head editando poi il file xorg.conf (allegato) senza però riuscire
a rendere l'ouput video esteso ma con il risultato di avere la stessa
immagine duplicata sui monitor. 
Le guide consultate non mi hanno aiutato a risolvere il problema.
P.S. la scheda funziona (ho provato con window XP).
-------------- parte successiva --------------
# /etc/X11/xorg.conf (xorg X Window System server configuration file)
#
# This file was generated by dexconf, the Debian X Configuration tool, using
# values from the debconf database.
#
# Edit this file with caution, and see the /etc/X11/xorg.conf manual page.
# (Type "man /etc/X11/xorg.conf" at the shell prompt.)
#
# This file is automatically updated on xserver-xorg package upgrades *only*
# if it has not been modified since the last upgrade of the xserver-xorg
# package.
#
# If you have edited this file but would like it to be automatically updated
# again, run the following command:
#   sudo dpkg-reconfigure -phigh xserver-xorg

Section "Files"
	FontPath	"/usr/share/X11/fonts/misc"
	FontPath	"/usr/share/X11/fonts/cyrillic"
	FontPath	"/usr/share/X11/fonts/100dpi/:unscaled"
	FontPath	"/usr/share/X11/fonts/75dpi/:unscaled"
	FontPath	"/usr/share/X11/fonts/Type1"
	FontPath	"/usr/share/X11/fonts/CID"
	FontPath	"/usr/share/X11/fonts/100dpi"
	FontPath	"/usr/share/X11/fonts/75dpi"
        # paths to defoma fonts
	FontPath	"/var/lib/defoma/x-ttcidfont-conf.d/dirs/TrueType"
	FontPath	"/var/lib/defoma/x-ttcidfont-conf.d/dirs/CID"
EndSection

Section "Module"
	Load	"GLcore"
	Load	"bitmap"
	Load	"ddc"
	Load	"dri"
	Load	"extmod"
	Load	"freetype"
	Load	"glx"
	Load	"int10"
	Load	"type1"
	Load	"vbe"
EndSection

Section "InputDevice"
	Identifier	"Generic Keyboard"
	Driver		"kbd"
	Option		"CoreKeyboard"
	Option		"XkbRules"	"xorg"
	Option		"XkbModel"	"pc105"
	Option		"XkbLayout"	"it"
EndSection

Section "InputDevice"
	Identifier	"Configured Mouse"
	Driver		"mouse"
	Option		"CorePointer"
	Option		"Device"		"/dev/input/mice"
	Option		"Protocol"		"ImPS/2"
	Option		"Emulate3Buttons"	"true"
	Option		"ZAxisMapping"		"4 5"
EndSection

Section "Device"
	Identifier	"ATI Technologies, Inc. Radeon 7500 (RV200 QW)"
	Driver		"ati"
	BusID		"PCI:1:0:0"
EndSection

Section "Monitor"
	Identifier	"L17AX"
	Option		"DPMS"
EndSection

Section "Screen"
	Identifier	"Default Screen"
	Device		"ATI Technologies, Inc. Radeon 7500 (RV200 QW)"
	Monitor		"L17AX"
	DefaultDepth	24
	SubSection "Display"
		Depth		1
		Modes		"1280x1024" "1024x768" "832x624" "800x600" "720x400" "640x480"
	EndSubSection
	SubSection "Display"
		Depth		4
		Modes		"1280x1024" "1024x768" "832x624" "800x600" "720x400" "640x480"
	EndSubSection
	SubSection "Display"
		Depth		8
		Modes		"1280x1024" "1024x768" "832x624" "800x600" "720x400" "640x480"
	EndSubSection
	SubSection "Display"
		Depth		15
		Modes		"1280x1024" "1024x768" "832x624" "800x600" "720x400" "640x480"
	EndSubSection
	SubSection "Display"
		Depth		16
		Modes		"1280x1024" "1024x768" "832x624" "800x600" "720x400" "640x480"
	EndSubSection
	SubSection "Display"
		Depth		24
		Modes		"1280x1024" "1024x768" "832x624" "800x600" "720x400" "640x480"
	EndSubSection
EndSection

Section "ServerLayout"
	Identifier	"Default Layout"
	Screen		"Default Screen"
	InputDevice	"Generic Keyboard"
	InputDevice	"Configured Mouse"
EndSection

Section "DRI"
	Mode	0666
EndSection