The 1.3 update is the one I tried manually, and it tells me I don't need it, but I doubt that's the case, given the power issues with the machine, which were not present before the update.
If I open package contents and try to run it anyway, I get: "An unexpected error occurred. Your firmware can not be updated. (internal error 21 : 0)".
If I try to run the executable in the Terminal, I get the error I described earlier: "Error parsing file version '0.000'."
I just tried the 1.3 restoration CD, but I can't put the computer in the right state as described here
. In order to boot the computer at all, I have to pull AC and battery, wait a while, and plug it in, at which point it boots automatically. If I try normally, the computer dies 2 seconds after hitting power. Either way, I can't hold down power long enough for it to attempt to use the CD.