I'm having trouble with a second monitor in a fresh installation of 12.04LTS. I'm on a desktop with an ATI Radeon 7500 and I have two identical LG monitors that each support 1920x1080. The second monitor is connected with HDMI and seems to work fine at resolutions less than 1920x1080. The DVI monitor is working correctly at 1920x1080. I've been trying to follow various posts on these forums, installing fglrx and the updated version as well. I've also set the resolution for both monitors in the Catalyst Control Center as well as in the Ubuntu Displays setting, and everything is set to 1920x1080. Am I missing a modeline or something? Can anyone tell me why the monitor works for everything except this resolution? I'm pretty stuck at this point. Thanks so much in advance for any advice at all.

Perhaps I have installed the drivers incorrectly, or in the wrong order?

Additionally, fglrxinfo yields the following:
display: :0 screen: 0
OpenGL vendor string: Advanced Micro Devices, Inc.
OpenGL renderer string: AMD Radeon HD 7500 Series
OpenGL version string: 4.2.11627 Compatibility Profile Context

A copy of my /etc/X11/xorg.conf file is pasted here:

Section "ServerLayout"
Identifier "amdcccle Layout"
Screen 0 "amdcccle-Screen[1]-0" 0 0
EndSection

Section "Module"
EndSection

Section "Monitor"
Identifier "0-DFP5"
Option "VendorName" "ATI Proprietary Driver"
Option "ModelName" "Generic Autodetecting Monitor"
Option "DPMS" "true"
Option "PreferredMode" "1920x1080"
Option "TargetRefresh" "60"
Option "Position" "1920 0"
Option "Rotate" "normal"
Option "Disable" "false"
EndSection

Section "Monitor"
Identifier "0-DFP6"
Option "VendorName" "ATI Proprietary Driver"
Option "ModelName" "Generic Autodetecting Monitor"
Option "DPMS" "true"
Option "PreferredMode" "1920x1080"
Option "TargetRefresh" "60"
Option "Position" "0 0"
Option "Rotate" "normal"
Option "Disable" "false"
EndSection

Section "Device"
Identifier "ATI radeon 6870"
Driver "fglrx"
BusID "PCI:1:0:0"
EndSection

Section "Device"
Identifier "amdcccle-Device[1]-0"
Driver "fglrx"
Option "Monitor-DFP5" "0-DFP5"
Option "Monitor-DFP6" "0-DFP6"
BusID "PCI:1:0:0"
EndSection

Section "Screen"
Identifier "amdcccle-Screen[1]-0"
Device "amdcccle-Device[1]-0"
DefaultDepth 24
SubSection "Display"
Viewport 0 0
Virtual 3840 1920
1,1 Top


The xrandr command yields:

xrandr
Screen 0: minimum 320 x 200, current 3840 x 1080, maximum 3840 x 1920
DFP1 disconnected (normal left inverted right x axis y axis)
DFP2 disconnected (normal left inverted right x axis y axis)
DFP3 disconnected (normal left inverted right x axis y axis)
DFP4 disconnected (normal left inverted right x axis y axis)
DFP5 connected 1920x1080+1920+0 (normal left inverted right x axis y axis) 510mm x 290mm
1920x1080 60.0*+ 50.0 59.9 30.0 25.0 30.0
1776x1000 50.0 59.9 25.0 30.0
1680x1050 50.0 60.0
1400x1050 50.0 60.0
1600x900 50.0 60.0
1360x1024 50.0 60.0
1280x1024 50.0 75.0 60.0
1440x900 50.0 60.0
1280x960 50.0 75.0 60.0
1152x864 50.0 59.9 75.0
1280x768 50.0 75.0 60.0
1280x720 60.0 50.0 59.9
1024x768 50.0 75.0 60.0
1152x648 50.0 59.9
800x600 50.0 75.0 60.3 56.2
720x480 50.0 60.0 59.9
640x480 50.0 75.0 60.0 59.9
DFP6 connected 1920x1080+0+0 (normal left inverted right x axis y axis) 510mm x 290mm
1920x1080 59.9*+
1680x1050 60.0
1400x1050 60.0
1600x900 60.0
1360x1024 60.0
1280x1024 75.0 60.0
1440x900 60.0
1280x960 75.0 60.0
1152x864 59.9 75.0
1280x768 75.0 60.0
1280x720 75.0 60.0
1024x768 75.0 60.0
800x600 75.0 60.3 56.2
640x480 75.0 59.9
CRT1 disconnected (normal left inverted right x axis y axis)


Any advice at all is greatly appreciated, pretty stumped on this one.