When you say "surround sound" do you mean dolby digital 5.1 surround sound or a little older system like a dolby pro-logic system?
Is your dvd player connected to your sound system digitally or with analog cables?
If the DVD player is connected digitally and you have a 5.1 system, you may need to go into the setup menu of the DVD player,not the setup menu of the DVD but the players' setup menu. Go to "output" or "audio setup" check for a setting called "data stream" or "output type" make sure it is set to "Dolby Digital" or "raw" and not "PCM". Otherwise,if your system is setup with 5 wires, it sounds as if the center channel wire is bad or possibly the center channel speaker or speaker wire is bad.