look for the website for your make of dvd player (sony, panasonic etc) contact them and ask for a "firmware upgrade disc". they should send you one free. then simply load in your player and it will download updated firmware and should sort out problems on your dvd player. however if your player refuses to load this disc, it will mean your player will have to be repaired. if its warranty has expired, you will probably be better off just buying a new dvd player.
hope this helps.
martin.
January 2005