I also have a sony 505 demo unit and have tried to follow this post down to a T multiple times. Where mine differs from Debby's is when i run the flasher card and press 7 it says "error copying lipfskLoad to /tmp/
Now i didn't have a tmp folder in the root of the card. So i created a new folder and named it "tmp".
Every time i run the sony updated it says already up to date.
Anyone have any ideas?