Its likely that you are running out of pixmap memory or the server is
having trouble allocating those pixmaps.

Out of curiousity, do you get any messages from compiz in a console
which say something like "failed to bind pixmap to texture" ?

On Thu, Apr 7, 2011 at 12:38 PM, <email address hidden>
<email address hidden> wrote:
> Yes- I observe that the larger the window, the more likely it is to be
> blank. When (enlarging) a window, the size can be increased up to a
> certain point at which the window goes blank.
>
> --
> You received this bug notification because you are a member of Unity
> Bugs, which is subscribed to unity in Ubuntu.
> https://bugs.launchpad.net/bugs/729979
>
> Title:
>  Windows sometimes become blank/transparent when changing focus to them
>  in natty
>
> Status in “compiz” package in Ubuntu:
>  Invalid
> Status in “unity” package in Ubuntu:
>  Invalid
>
> Bug description:
>  Binary package hint: compiz
>
>  When switching focus from one window to another, the target window may
>  become blank. See the attached screenshot, where I opened two gnome-
>  terminals and clicked on their titlebars alternately - the issue was
>  triggered after about 5-10 clicks. I've had this happen on other
>  appications too, e.g. software-centre, empathy, etc.
>
>  Doing shade+unshade, maximizing or clicking away from the problematic
>  window usually makes the window contents come back. The window remains
>  responsive to both keyboard and mouse (by the way, in the screenshot
>  the mouse cursor was an I-beam before I pressed PrtScr).
>
>  This is on up-to-date natty, installed from scratch using the daily
>  image from the 1st of March.
>
>  ProblemType: Bug
>  DistroRelease: Ubuntu 11.04
>  Package: compiz 1:0.9.4-0ubuntu3
>  ProcVersionSignature: Ubuntu 2.6.38-5.32-generic 2.6.38-rc6
>  Uname: Linux 2.6.38-5-generic x86_64
>  NonfreeKernelModules: nvidia
>  .proc.driver.nvidia.gpus.0: Error: [Errno 21] Is a directory: '/proc/driver/nvidia/gpus/0'
>  .proc.driver.nvidia.registry: Binary: ""
>  .proc.driver.nvidia.version:
>   NVRM version: NVIDIA UNIX x86_64 Kernel Module  270.29  Wed Feb 23 16:18:35 PST 2011
>   GCC version:  gcc version 4.5.2 (Ubuntu/Linaro 4.5.2-3ubuntu3)
>  Architecture: amd64
>  CompizPlugins: [core,bailer,detection,composite,opengl,decor,imgsvg,resize,resizeinfo,mousepoll,wall,regex,animation,place,blur,compiztoolbox,text,session,grid,put,imgpng,imgjpeg,gnomecompat,commands,copytex,wobbly,annotate,move,vpswitch,workarounds,expo,ezoom,staticswitcher,fade,scale,scaleaddon,unityshell]
>  CompositorRunning: compiz
>  Date: Sun Mar  6 02:42:49 2011
>  DistUpgraded: Log time: 2011-03-03 20:05:16.908415
>  DistroCodename: natty
>  DistroVariant: ubuntu
>  DkmsStatus: nvidia-current, 270.29, 2.6.38-5-generic, x86_64: installed
>  GraphicsCard:
>   nVidia Corporation ION VGA [GeForce 9400M] [10de:0876] (rev b1) (prog-if 00 [VGA controller])
>     Subsystem: ASUSTeK Computer Inc. Device [1043:8402]
>  InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Alpha amd64 (20110301.1)
>  InstallationMedia_: Ubuntu 11.04 "Natty Narwhal" - Alpha amd64 (20110301.1)
>  JockeyStatus: xorg:nvidia_current - NVIDIA accelerated graphics driver (Proprietary, Enabled, In use)
>  Lsusb:
>   Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
>   Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
>   Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
>   Bus 001 Device 002: ID 13d3:5126 IMC Networks
>   Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
>  MachineType: ASUSTeK Computer INC. 1201N
>  PackageArchitecture: all
>  ProcEnviron:
>   LANGUAGE=en_GB:en
>   PATH=(custom, user)
>   LANG=en_GB.UTF-8
>   SHELL=/bin/bash
>  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.38-5-generic root=UUID=56551fbd-03c7-48af-b7f4-c8f165bc66ed ro quiet splash vt.handoff=7
>  ProcVersionSignature_: Ubuntu 2.6.38-5.32-generic 2.6.38-rc6
>  Renderer: Unknown
>  SourcePackage: compiz
>  UpgradeStatus: Upgraded to natty on 2011-03-03 (2 days ago)
>  dmi.bios.date: 04/29/2010
>  dmi.bios.vendor: American Megatrends Inc.
>  dmi.bios.version: 0326
>  dmi.board.asset.tag: To Be Filled By O.E.M.
>  dmi.board.name: 1201N
>  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.:bvr0326:bd04/29/2010:svnASUSTeKComputerINC.:pn1201N:pvrx.x:rvnASUSTeKComputerINC.:rn1201N:rvrx.xx:cvnASUSTeKComputerINC.:ct10:cvrx.x:
>  dmi.product.name: 1201N
>  dmi.product.version: x.x
>  dmi.sys.vendor: ASUSTeK Computer INC.
>  version.compiz: compiz 1:0.9.4-0ubuntu3
>  version.libdrm2: libdrm2 2.4.23-1ubuntu3
>  version.libgl1-mesa-glx: libgl1-mesa-glx 7.10.1~git20110215.cc1636b6-0ubuntu2
>  version.nvidia-graphics-drivers: nvidia-graphics-drivers N/A
>  version.xserver-xorg: xserver-xorg 1:7.6~3ubuntu11
>  version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:6.14.0-0ubuntu2
>  version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.14.0-4ubuntu1
>  version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:0.0.16+git20110107+b795ca6e-0ubuntu5
>



-- 
Sam Spilsbury