XO-1 developer key does not work

[Sridhar Dhanapalan]

I am trying to put a permanent developer key on an XO-1. I have been
following the steps at
http://wiki.laptop.org/go/Activation_and_developer_keys

First, I created the key using devkey.html. Then I copied develop.sig
to /security on the XO. After rebooting, I still see a wp tag in
/ofw/mfg-data.

Then I copied develop.sig to /security to a USB drive. Turning the XO
on with the drive plugged in makes no difference. If I hold down the
tick key while turning on, I get the messages:

  trying disk:\security\develop.sig
  Devel key  No matching records
  ...
  Trying nand:\security\develop.sig
  Devel key  No matching records

I tried several FAT32-formatted USB drives, including one that I have
used to upgrade to the latest signed firmware.

Can anyone help out?

Thanks,
Sridhar