hello,
You can only flash with backup from 20-40 from the SAME PHONE! if you flash with backup from 20-40 from other phone, you will loose your phone. From other phones you can only flash till 003D00000, otherwise you'll mess eeprom!
Check here for working backups and start adresses
http://doedelmania.ontheweb.nl/
Best Regards,
KiCK