Mitch,
One of the LBA NAND test machines killed it's MBR.
It started with a failed comparison of the commonly
written blocks, then stopped talking to the device at
all.
On reboot, fdisk showed no partition table.
dd of /dev/lba showed all FFs for the first 16K,
then 00 for the next 2K, then data.
Suggestions on how to proceed w. debugging
are welcome.
wad