Ubuntu 12.04 Screen Problems

Ubuntu 12.04 LTS

apt-cache policy pkgname
N: Unable to locate package pkgname

When i first updated ubuntu 12.04, all i got at first was a black screen. But thanks to some of you guys, the problem was fixed.
Since then, well i've been out of internet for a while, but a major trouble remains with my screen.
The display of the screen appears relatively normal on its top half. But its bottom is either black or covered with some writings from the boot up. Moreover, the interaction with top half of the screen is messed up. The screen goes white, black or kind of splits itself wherever the mouse's cursor goes.
Can anyone help me ? Thanks so much in advance !!

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: linux-image-3.2.0-24-generic 3.2.0-24.39
ProcVersionSignature: Ubuntu 3.2.0-24.39-generic 3.2.16
Uname: Linux 3.2.0-24-generic i686
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.24.
AplayDevices:
 **** List of PLAYBACK Hardware Devices ****
 card 0: MID [HDA Intel MID], device 0: ALC269 Analog [ALC269 Analog]
   Subdevices: 0/1
   Subdevice #0: subdevice #0
ApportVersion: 2.0.1-0ubuntu8
Architecture: i386
ArecordDevices:
 **** List of CAPTURE Hardware Devices ****
 card 0: MID [HDA Intel MID], device 0: ALC269 Analog [ALC269 Analog]
   Subdevices: 1/1
   Subdevice #0: subdevice #0
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: charlotte2 1482 F.... pulseaudio
 /dev/snd/pcmC0D0p: charlotte2 1482 F...m pulseaudio
CRDA: Error: [Errno 2] No such file or directory
Card0.Amixer.info:
 Card hw:0 'MID'/'HDA Intel MID at 0xf3f38000 irq 23'
   Mixer name : 'Realtek ALC269'
   Components : 'HDA:10ec0269,104383ce,00100004'
   Controls : 17
   Simple ctrls : 9
Date: Wed Jun 6 05:09:43 2012
HibernationDevice: RESUME=UUID=01f84311-6c1a-4cb7-9a0d-51ede255c6de
InstallationMedia: Ubuntu-Netbook 10.04 "Lucid Lynx" - Release i386 (20100429.4)
IwConfig: Error: [Errno 2] No such file or directory
MachineType: ASUSTeK Computer INC. 1101HA
ProcFB: 0 psbfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.2.0-24-generic root=UUID=5d7215b4-c21b-4096-a33b-cc81377edbb6 ro quiet splash console=tty1 pci=use_crs vt.handoff=7
RelatedPackageVersions:
 linux-restricted-modules-3.2.0-24-generic N/A
 linux-backports-modules-3.2.0-24-generic N/A
 linux-firmware 1.79
RfKill: Error: [Errno 2] No such file or directory
SourcePackage: linux
StagingDrivers: psb_gfx
UdevDb: Error: [Errno 2] No such file or directory
UpgradeStatus: Upgraded to precise on 2012-05-17 (19 days ago)
dmi.bios.date: 06/17/2009
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 0205
dmi.board.asset.tag: To Be Filled By O.E.M.
dmi.board.name: 1101HA
dmi.board.vendor: ASUSTeK Computer INC.
dmi.board.version: x.xx
dmi.chassis.asset.tag: 0x00000000
dmi.chassis.type: 10
dmi.chassis.vendor: ASUSTek Computer INC.
dmi.chassis.version: x.x
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr0205:bd06/17/2009:svnASUSTeKComputerINC.:pn1101HA:pvrx.x:rvnASUSTeKComputerINC.:rn1101HA:rvrx.xx:cvnASUSTekComputerINC.:ct10:cvrx.x:
dmi.product.name: 1101HA
dmi.product.version: x.x
dmi.sys.vendor: ASUSTeK Computer INC.