New receiver and subwoofer sometimes not receiving signal

[PCFan]

Yesterday I returned a receiver because of an intermittent audio drop-out problem when I had my center speaker installed. I exchanged it for an Onkyo TX-SR507 receiver. I'm having a problem with my subwoofer not getting a signal during a DVD I was watching, Night Court: Season 2. I noticed the problem when there was a lack of bass in the opening and closing credits of Night Court with this receiver and turning subwoofer off through the receiver it still sound the same. The receiver I returned did send a signal to my subwoofer during watching this DVD but with this one I get no bass from the subwoofer with this DVD. I also don't get bass from the subwoofer in the top menu of Pumping Iron DVD while the music is playing until the movie starts. I read the manual and it said that the source material needs to have an LFE signal to get sound from the subwoofer. I don't have this problem when playing my Xbox 360 or playing Slacker Radio through my Blu-Ray player. I'm using a Yamaha 100watt subwoofer that came with my Yamaha 5.1 speaker package. Is there a way to make my subwoofer handle the bass from every source besides just ones with LFE material?