I've got SV-DVD645 (with DivX playback) but can't make it region-free:
1. If I perform usual steps I can see "5" at the top-left corner after "53814" sequence for Region 5 and can replace it with "9". But it doens't really change the code.
2. Play + Stop or Play + FF don't work.
3. RF + FF shows RESET Screen and Software version (it's "Macrovision E7102")