Just got this DTI this weekend from a friend. Hooked it up and it does make a desirable improvement. However, the two Lock Lights Primary andSecondary work kind of strange. Most of the time just the Primary one is on and sometimes during playback the Secondary light comes on stays on for awile then goes out. Sometimes the Secondary light just flashes on and off. Don't know anything about the unit, just I like the improvement. Can anybody explain what this is all about and if it is normal or defective? Any help would be appreciated. Thanks, Bob