4Dsystems Display Shield problem

I have the 4DSystems 4Display-Shield-160 shield. I put together a spectrum analyzer and noticed black vertical lines on the screen. I have since discovered that these lines are color dependent. I get different lines for green, blue and red when I display a solid color. Thought it might be a hardware issue with the flexible connector but I can't see how that could result in color dependent lines. Anyone else had this issue?