I got the same SWL Error after selecting Downgrade Firmware from the setup menu and then inserting the CD.

I then re-burnt the CD at x1, selected Downgrade Firmware and inserted the newly burnt CD.

This started software load from the CD, but then I got the error that the maximum number of attempts had been reached, and to perform the "Setup" + "Eject" + "Info" reboot.

So I then pressed "Setup" + "Eject" + "Info", which rebooted the unit and the CD installed without fuss.

So I'm not really sure which method actually enabled the update of the logo.