Left taskbar and top menubar only appear intermittently

Binary package hint: ubuntu-netbook

Using Ubuntu 10.10 netbook remix as a "10 foot GUI". Running on HP T5735 thin client attached via DVI port to Panasonic plasma TV. Left hand taskbar and top menubar show as purple bars of correct thickness but no icons or text. If I move the mouse over the taskbar, it shows a white box framed by a black box, of different widths. By guessing what they are, I can click on a box and select a taskbar app e.g. 2nd from bottom is Applications. Sometimes when redrawing screen, the icons flash up for a second, and disappear again.

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
Architecture: i386
CurrentDmesg:
 [ 15.232756] ADDRCONF(NETDEV_UP): wlan1: link is not ready
 [ 25.507237] EXT4-fs (sdb2): re-mounted. Opts: errors=remount-ro,commit=0
 [ 53.209382] EXT4-fs (sdb2): re-mounted. Opts: errors=remount-ro,commit=0
DRM.card0.DVI.D.1:
 status: connected
 enabled: enabled
 dpms: On
 modes: 1920x1080 1920x1080 1280x720 1280x720 720x576
 edid-base64: AP///////wA0qZagAQEBAQATAQOAAAB4Ctr/o1hKoikXSUsAAAABAQEBAQEBAQEBAQEBAQEBAjqA0HI4LUAQLEWAuoghAAAeAjqAGHE4LUBYLEUAuoghAAAeAAAA/ABQYW5hc29uaWMtVFYKAAAA/QAXPQ9EDwAKICAgICAgAeICAyVyUJ+QFAUgEwQSAxECFgcVBgEjCQcBZwMMACAAuCbjBQMBAR2A0HIcFiAQLCWAuoghAACeAR2AGHEcFiBYLCUAuoghAACeAR0AvFLQHiC4KFVAuoghAAAeAR0AclHQHiBuKFUAuoghAAAejArQkCBAMSAMQFUAuoghAAAYGw==
DRM.card0.VGA.1:
 status: disconnected
 enabled: disabled
 dpms: On
 modes:
 edid-base64:
Date: Wed Mar 9 10:46:06 2011
GdmLog1: Error: command ['gksu', '-D', 'Apport', '--', 'cat', '/var/log/gdm/:0.log.1'] failed with exit code 1: cat: /var/log/gdm/:0.log.1: No such file or directory
GdmLog2: Error: command ['gksu', '-D', 'Apport', '--', 'cat', '/var/log/gdm/:0.log.2'] failed with exit code 1: cat: /var/log/gdm/:0.log.2: No such file or directory
InstallationMedia: Ubuntu-Netbook 10.10 "Maverick Meerkat" - Release i386 (20101007)
MachineType: Hewlett-Packard hp t5735
ProcCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.35-22-generic root=UUID=8db46680-ccf7-46f9-aa03-e6fbde2e0e19 ro quiet splash
ProcEnviron:
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: xorg
Symptom: display
dmi.bios.date: 03/10/2008
dmi.bios.vendor: Phoenix Technologies, LTD
dmi.bios.version: 786R4 v1.03
dmi.board.name: 0ACCh
dmi.board.vendor: Hewlett-Packard
dmi.chassis.asset.tag: 000000000000000000
dmi.chassis.type: 3
dmi.chassis.vendor: Hewlett-Packard
dmi.modalias: dmi:bvnPhoenixTechnologies,LTD:bvr786R4v1.03:bd03/10/2008:svnHewlett-Packard:pnhpt5735:pvr:rvnHewlett-Packard:rn0ACCh:rvr:cvnHewlett-Packard:ct3:cvr:
dmi.product.name: hp t5735
dmi.sys.vendor: Hewlett-Packard
glxinfo: Error: [Errno 2] No such file or directory
system:
 distro: Ubuntu
 codename: maverick
 architecture: i686
 kernel: 2.6.35-22-generic