HELP: Bel Canto DAC and my cables aren't working..

I bought a used Bel Canto DAC1 to use with a Pioneer DVD system that I have. I got the DAC for a good price and I couldn't resist. Ok, so it arrives in good condition and I use a Monster Digital cable that I have and it doesn't work. I fiddle with everything and nothing. So, I take off the Monster and I try an Audioquest cable and still nothing. I am thinking that something is broken after I try changing everything, but the kitchen sink. Ok, lastly, I have one last test to do and the cables are out of reach, so I plug in a cheap Radio Shack cable and HOLY MOLY, the music comes to life. So, I think, I must have set something right, so I reach for one of my better cables and guess what? None of the better cables work. The only thing that works is the cheap Radio Shack cable.

What am I doing wrong?