Flicking display when things scroll, appear, or disappear (nVidia GeForce 6150)

Binary package hint: xorg

The display flickers, for a frame or so showing what looks like other parts of the screen (perhaps previously displayed images) offset, typically along the lower half of the screen. It generally happens when there are updates - particularly new or closed windows, menus, etc. Typing doesn't seem to do it as often, but scrolling sometimes does, as does switching windows.

This problem appeared as soon as I booted into the Ubuntu 10.04.1 livecd's desktop. (which would have been using the nouveau driver) and I installed anyway hoping it would be fixed by the proprietary nVidia drivers or other settings. I have tried a lot to fix this, with no luck (it's still doing it as I write this) Attempts included:
All available versions of the nVidia proprietary drivers - 96, 173, current (195 if I recall in 10.04, 256 in 10.10)
All settings of Preferences - Appearance - Visual Effects
Upgrading to 10.10 (note, currently in beta or maybe RC)
Different refresh rates.

I don't know what else to try, and this problem isn't exactly easy to search for.
Please let me know if there are things I can try, or more info I can provide.

This issue does not occur in Windows XP on the same computer.

(Note, I only have access to this computer for a couple days every two weeks or so. Please be patient if I can't respond right away to suggestions or requests for info that I need to use this PC to answer.)

ProblemType: Bug
DistroRelease: Ubuntu 10.10
Package: xorg 1:7.5+6ubuntu3
ProcVersionSignature: Ubuntu 2.6.35-22.33-generic 2.6.35.4
Uname: Linux 2.6.35-22-generic i686
NonfreeKernelModules: nvidia
.proc.driver.nvidia.version:
 NVRM version: NVIDIA UNIX x86 Kernel Module 256.53 Fri Aug 27 21:03:42 PDT 2010
 GCC version: gcc version 4.4.5 (Ubuntu/Linaro 4.4.4-14ubuntu5)
Architecture: i386
CurrentDmesg:
 [ 18.901921] EXT4-fs (sdb2): re-mounted. Opts: errors=remount-ro,commit=0
 [ 20.249989] EXT4-fs (sdb2): re-mounted. Opts: errors=remount-ro,commit=0
 [ 27.904019] eth0: no IPv6 routers present
 [ 79.648049] Clocksource tsc unstable (delta = -266058656 ns)
 [ 1283.112033] hda_codec: invalid CONNECT_LIST verb 12[2]:2100
Date: Wed Sep 29 23:26:59 2010
DkmsStatus: nvidia-current, 256.53, 2.6.35-22-generic, i686: installed
InstallationMedia: Ubuntu 10.04.1 LTS "Lucid Lynx" - Release i386 (20100816.1)
MachineType: System manufacturer System Product Name
ProcCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.35-22-generic root=UUID=90771a5c-b757-424d-8014-13f7d1e56441 ro quiet splash
ProcEnviron:
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: xorg
Symptom: display
dmi.bios.date: 10/05/2005
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 0403
dmi.board.asset.tag: To Be Filled By O.E.M.
dmi.board.name: A8N-VM CSM
dmi.board.vendor: ASUSTeK Computer INC.
dmi.board.version: Rev 1.xx
dmi.chassis.asset.tag: Asset-1234567890
dmi.chassis.type: 3
dmi.chassis.vendor: Chassis Manufacture
dmi.chassis.version: Chassis Version
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr0403:bd10/05/2005:svnSystemmanufacturer:pnSystemProductName:pvrSystemVersion:rvnASUSTeKComputerINC.:rnA8N-VMCSM:rvrRev1.xx:cvnChassisManufacture:ct3:cvrChassisVersion:
dmi.product.name: System Product Name
dmi.product.version: System Version
dmi.sys.vendor: System manufacturer
system:
 distro: Ubuntu
 codename: maverick
 architecture: i686
 kernel: 2.6.35-22-generic