[NiLuJe]

Err, just to be sure, you're doing the update via the Settings Menu, not rebooting your kindle with a custom update*.bin in the usb root? And it's the right *.bin for your device?

The jailbreak should fail with a U006 error if memory serves me. That it fails with another error code means something went wrong...

The U007 error for the ss hack is normal, it's because the jailbreak failed.

Not sure what the 0003 error means though... Try redownloading the zip from the first post, and reuploading the *bin file, maybe it got corrupted somehow...

Also, since it seems to be a very new Kindle, what's the full version tag at the bottom of the Settings page? That's a very long shot, but maybe your Kindle has a newer 2.5.3 build than the one widely available, with this particular jailbreak hole plugged...