I had major issues with my QNIX 2710 after I left it on overnight with garbled screen resolution (Funny colors all over the screen). I fixed the resolution problem and the weird image corruption problems went away completely after a couple hours. The issue I had was like a temporary burn-in (like plasmas). Doubt your have the same issue but try a different DL-DVI cable and leave it on for an hour.
Um I disassembled my Qnix qx2710 a while ago and I remember that one cord was not fitted back in all the way and I had the same effect on my screen. All it took was fitting it back in correctly and the screen was back to normal. Perhaps you might consider checking that out before giving up on it.