I think I'm having the same problem.

2008OS cloned to 4GB SDHC card worked without (too many) problems.

2008OS cloned to 16GB SDHC card - unable to boot from the card.

Card is partitioned like this:

Nokia-N800-50-2:~# sfdisk -lx

Disk /dev/mmcblk0: 503680 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/mmcblk0p1 0+ 407679 407680- 13045759+ b W95 FAT32
/dev/mmcblk0p2 407680 503679 96000 3072000 83 Linux
/dev/mmcblk0p3 0 - 0 0 0 Empty
/dev/mmcblk0p4 0 - 0 0 0 Empty

I suspect that the boot menu process cant find the 2nd partition at such a high starting block... (I could very well be wrong, it's a guess).

Using the same card, if I partition the card so that there is a ~3GB ext2 partition first, and the remaining space is FAT32 the card *wiil* boot (however the /media/mmc2 is mounted as the first ext2 partition, not the FAT32 partition when booting from flash, the FAT32 partition is not mounted at all.)

Would very much welcome anyone's thoughts.

Thanks,
Andy