Four Monitor X-Windows

Objective

To get my four monitor X-Windows configuration to work properly with Xinerama. Currently, the mouse pointer moves among all monitors, but cannot seem to drag open application window between monitors of differing cards.

General Information

Video Cards

• ATI Radeon X1600 Pro PCI-E (Sapphire)
• Nvidia GEForce 8400 GS PCI

Note: Each card has dual port VGA / DVI

OS Information

Linux Distribution: Ubuntu Studio 10.10
Kernel Version: Linux studio 2.6.35-23-generic #37-Ubuntu SMP Fri Nov 5 19:16:29 UTC 2010 x86_64 GNU/Linux

X-Windows Information

[ xorg.conf ]

Additional Information

Xrandr Commands (at system startup):

• xrandr --output VGA-0 --mode 1440x900 --pos 1440x0 --screen 1 (right two monitors)
• xrandr --output VGA2 --mode 1440x900 --pos 1440x0 --screen 0 (left two monitors)

Other Observations

• Only able to get 4 monitor system running as far as possible (except span application window between cards) by setting PCI card as primary Video default in BIOS (auto didn't seem to work correctly)
• Radeon error upon boot-up: ACPI
• When enabling xinerama (i.e. In "Server Layout: Option "Xinerama" "1" ),