Problem with playback on 5001

This has nothing to do with firmware (at least not that I know of yet).

I have the liteon LVW-5001 recorder. I have a gamecube connected in to it and it then outputs to a VCR which then goes to the TV. When I play gamecube everything is fine but when I try to play a DVD, the picture darkens, gets quite a bit of static, then returns to normal. It repeats this process every 15 seconds or so. Has anybody ever had this problem before/know how to fix it.

P.S. forgive me if this question has already been asked, I tried searching but have yet to find anything. I belong to numerous other forums and know what it feels like to answer the same question 10 times over.

if you diconnect the gamecube how is the DVD playback quality?

I fixed it, the problem was with my VCR. I switched it out with a different one and the interference went away.