running a Ubuntu distribution at BeagleBoard-XM revB

Hi all:
I have tried to run a Ubuntu distribution at BeagleBoard-XM RevB. I
followed instructions shown at
https://wiki.ubuntu.com/ARM/OMAPHeadlessInstall linked from
http://elinux.org/BeagleBoardUbuntu https://wiki.ubuntu.com/ARM/OMAP
(4 Canonical Pre-Installed Images 4.1 Natty 11.04).But it dosen't
work, some problems exist.
I made the SD card an the following steps:
1 I have an 8GB SD card
2 I download ubuntu-11.04-preinstalled-headless-armel+omap.img.gz from
http://cdimage.ubuntu.com/releases/11.04/release/
3 I run the following command to copy the image to the SD card:
  gunzip -c ubuntu-11.04-preinstalled-headless-armel+<omap

.img.gz | sudo dd bs=4M of=/dev/<device name>

  sync
4 Update for BeagleXM Rev B & Rev C
  (1)Download http://people.canonical.com/~tobin/natty/beagleXM-natty.tgz
  (2)Untar with "tar -zxf beagleXM-natty.tgz
  (3)Mount the first SD card partition at your host PC and copy uImage
to it. Unmount
  (4)Mount the second SD card partition at your host PC and copy
vmlinuz-2.6.38-8-omap to <mountpoint>/boot. Unmount

At last ,I switch on the board with the SD card inserted. Here is the
output of the serial:
......
U-Boot 2011.03 (Apr 20 2011 -
07:19:53)

OMAP3630/3730-GP ES2.0, CPU-OPP2, L3-165MHz, Max CPU Clock 1
Ghz
OMAP3 Beagle board + LPDDR/NAND
I2C: ready
DRAM: 512 MiB
NAND: 0 MiB
MMC: OMAP SD/MMC: 0
*** Warning - readenv() failed, using default
environment

In: serial
Out: serial
Err: serial
Beagle xM Rev A
No EEPROM on expansion board
Die ID
#74c800019ff80000015eeaa101010022
Hit any key to stop autoboot: 0
OMAP3 beagleboard.org # printenv
baudrate=115200
beaglerev=xMA
bootcmd=if mmc rescan ${mmcdev}; then if run loadbootscript; then run
bootscript
; else if run loaduimage; then run mmcboot; else run nandboot; fi; fi;
else
run
nandboot; fi
bootdelay=10
bootscript=echo Running bootscript from mmc ...; source $
{loadaddr}
buddy=none
console=ttyS2,115200n8
defaultdisplay=dvi
dieid#=74c800019ff80000015eeaa101010022
dvimode=1024x768MR-16@60
loadaddr=0x82000000
loadbootscript=fatload mmc ${mm
loaduimage=fatload mmc ${mmcdev} ${loadaddr}
uImage
mmcargs=setenv bootargs console=${console} mpurate=${mpurate} vram=$
{vram}
omapf
b.mode=dvi:${dvimode} omapfb.debug=y omapdss.def_disp=$
{defaultdisplay} root=$
{m
mcroot} rootfstype=${mmcrootfstype}
mmcboot=echo Booting from mmc ...; run mmcargs; bootm $
{loadaddr}
mmcdev=0
mmcroot=/dev/mmcblk0p2 rw
mmcrootfstype=ext3 rootwait
mpurate=1000
nandargs=setenv bootargs console=${console} mpurate=${mpurate} vram=$
{vram}
omap
fb.mode=dvi:${dvimode} omapfb.debug=y
omapds
nandroot} rootfstype=$
{nandrootfstype}
nandboot=echo Booting from nand ...; run nandargs; nand read $
{loadaddr}
280000
400000; bootm ${loadaddr}
nandroot=/dev/mtdblock4 rw
nandrootfstype=jffs2
usbtty=cdc_acm
vram=12M
Environment size: 1298/131068 bytes

......

Errors were found while checking the disk drive for /
Press F to attempt to fix the errors, I to ignore, S to skip mounting
or M for m
anual recovery

The disk drive for /tmp is not ready yet or not present
Continue to wait; or Press S to skip mounting or M for manual recovery
Ignoring errors with / at use[ 470.596893] EXT3-fs (mmcblk0p2):
error: ext3_rem
ount: Abort forced by user
request
mount: cannot remount block device /dev/mmcblk0p2 read-write, is write-
protected

mountall: mount / [1680] terminated with status 32
mountall: Filesystem could not be mounted: /

it stopped here.
I have tried many times and different images ,such as ubuntu-11.04-
preinstalled-netbook-armel+omap.img.gz
and ubuntu-netbook-10.10-preinstalled-netbook-armel+omap.img.gz. None
of them succeeded, have you run to
the same problem.What can I do to solve the problem, any suggestion?

I appreciate your time and concern very much.

                                     Best regards\!
                                     Sincerely
                                     Ying Cui\.

mount: cannot remount block device /dev/mmcblk0p2 read-write, is write-
protected

mountall: mount / [1680] terminated with status 32
mountall: Filesystem could not be mounted: /

it stopped here.
I have tried many times and different images ,such as ubuntu-11.04-
preinstalled-netbook-armel+omap.img.gz
and ubuntu-netbook-10.10-preinstalled-netbook-armel+omap.img.gz. None
of them succeeded, have you run to
the same problem.What can I do to solve the problem, any suggestion?

Maybe, try another SD Card?
-Joel