Sorry for reviving this old topic.
It seems, the firmware updater file on the page
http://www.powerdeveloper.org/platforms/efika/firmware became broken at some point, and that's why it didn't work for some people reporting it in this topic.
Fortunately I still had a version on my Efika's HDD, which I downloaded back in the days, which had a
different md5sum, and it was confirmed working by an user, who updated his Efika with it successfully just minutes ago.
So I contacted with the maintainer of
the firmware page, I sent him my file, and he replaced the file with my version. So anyone who had a problem with it previously, redownload, and try again!