why does the picture of the dvd goes back and fourth across the tv screen?

My dvd player , when I put the movie in the dvd player it is blury and it keeps going back and forth across the tv screen.

This is a bit odd. Can you be more pacific?

I once had a similar problem which I discovered was caused by my S-video cable; one of the prongs had broken off while I was changing stuff around. I ended up getting a flickering image in black and white.

So my first impression is that it's some sort of cable brew-ha-ha - have you recently changed your cables around? It could also be interference from something in your home, but I doubt that... your problem sounds a bit more complicated than simple interference.

I had this issue when I bought my first DVD player 12 or 13 years ago. Here is how I had it setup: I had a 19" CRT TV with a VCR hooked up to it via coax. Coax was the only input in the back of the TV. So I had to run the DVD player through the RCA jacks on the back of the VCR. So the DVD signal went from the DVD player into the VCR and then into the TV via the coax. I guess the DVD signal isn't meant to travel through a standard coax input and it gets distorted and I got the same type of picture issue you have. It wasn't as clear as it could have been, and it would wave from side to side every few seconds. Also the colors would bleed together. So at the time I just bought a new 32" TV with RCA jacks in the back. If oyu don't have the cash to throe down for a new TV (If this is even the issue in your case) you can buy a signal modulator from Radio Shack or some other electronics shop for $20 or so.

as with old video tapes, dvd's are also encrypted with macrovision...this only comes apparent when you run a dvd player signal through a vcr to your tv...this was done so you would not copy dvd's onto video tape...not that that is much of a problem in copying these days...just copy on a computer now