Code:
If there is anyone present who wants to upgrade the flash, let them speak now,
or forever hold their peace...


IIRC, this part is from the (usually) non-upgradeable part of flash. If it's not managing to run to this point consistently, then I suspect that your flash chip (or something else worse) is hosed somehow.

Code:
Couldn't lockdown flash (ram fault?)


...which is sort of implied by this.

And the "hold their peace" part is the prompt to the serial upgrader, so in case I am wrong, it might be worth persevering a few times with the upgrader, in case it does get to this point and then successfully reflash.
_________________________
-- roger