Desktop Display shows as laptop and resolution mismatch with monitor

Question

I have been using Ubuntu 12.04 without problem. After upgrading to 12.10 then 13.04, the display is messed up: under the setting, Displays setting shows as laptop, detection display button does not work, I can not change the resolution either. I am using a monitor with 1600x900 but the resolution in displays is set as 1280x1080. I have tried to reinstall the Ubuntu from CD, the problem is the same. I tried to install Ubuntu 13.04 on a new partition, then, the displays work ok. Anyone have idea how to fix this? Thanks a lot. Here is the output from the command below:

lspci -nnk | grep -iA3 vga

01:05.0 VGA compatible controller [0300]: Advanced Micro Devices [AMD] nee ATI RS780L [Radeon 3000] [1002:9616]
    Subsystem: ASUSTeK Computer Inc. Device [1043:8388]
02:00.0 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd. RTL8111/8168 PCI Express Gigabit Ethernet controller [10ec:8168] (rev 06)
    Subsystem: ASUSTeK Computer Inc. P8P67 and other motherboards [1043:8432]

The output from xrandr is:

xrandr: Failed to get size of gamma for output default Screen 0: minimum 640 x 400, current 1280 x 1024, maximum 1280 x 1024 default connected 1280x1024+0+0 0mm x 0mm 1280x1024 0.0* 1152x864 0.0
1024x768 0.0
800x600 0.0
640x480 0.0
720x400 0.0

Answer 1

my.friend. first login by recovery mode or nomodeset ( is best ) . nomodeset : after see grub press shift key or e key . find quiet splash and write nomodeset , after or befor quiet splash . dont forget space between. press f10 or ctrl+x to login . after login you first install linux-source and linux-header :

sudo apt-get install linux-headers

sudo apt-get install linux-source .

after it install good driver to fix . test it from additional driver .