mmm, I'm almost there... can anyone help, please?

n800 OS2008.

Carried out all the steps with no problems. I get the bootmenu, and can boot into flash as normal.

Performed an " ./nupgrade.sh wipe" on my newly partitioned external 8GB SD. Went well, ended:
...
/home/user/bin/tar: .: implausibly old time stamp 1970-01-01 01:00:00
Committing updates and Unmounting filesystems
Done

but when I select the second partition on "External SD card, partition 2, ext3", from the bootmenu, it says:

Boot from mmc12 failed, booting from flash

Here's my partition table; did I get it wrong?

Nokia-N800-50-2:~# sfdisk -l /dev/mmcblk1

Disk /dev/mmcblk1: 249296 cylinders, 4 heads, 16 sectors/track
Units = cylinders of 32768 bytes, blocks of 1024 bytes, counting from 0

Device Boot Start End #cyls #blocks Id System
/dev/mmcblk1p1 0+ 232911 232912- 7453183+ b W95 FAT32
/dev/mmcblk1p2 232912 249295 16384 524288 83 Linux
/dev/mmcblk1p3 0 - 0 0 0 Empty
/dev/mmcblk1p4 0 - 0 0 0 Empty

Nokia-N800-50-2:~# dumpe2fs -h /dev/mmcblk1p2
dumpe2fs 1.40.3 (05-Dec-2007)
Filesystem volume name: Sardine
Last mounted on: <not available>
Filesystem UUID: c59a9e84-b7a7-4160-8942-f7a7b9ff4d32
Filesystem magic number: 0xEF53
Filesystem revision #: 1 (dynamic)
Filesystem features: resize_inode dir_index filetype sparse_super
Filesystem flags: unsigned directory hash
Default mount options: (none)
Filesystem state: clean
Errors behavior: Continue
Filesystem OS type: Linux

Also, perhaps oddly, I'm unable to manually mount it:

Nokia-N800-50-2:~# mount -r /dev/mmcblk1p2 /mnt
mount: mounting /dev/mmcblk1p2 on /mnt failed
Nokia-N800-50-2:~# mount -r -t ext2 /dev/mmcblk1p2 /mnt
mount: mounting /dev/mmcblk1p2 on /mnt failed


any ideas, please? thanks much...