Lines during dvd play in Dell plasma 42"

[copiche]

Hey guys.
I have had my plasma for about 2 weeks now and during a dvd play (I have not checked during cable, hi def broadcasting yet) I started noticing lines like /\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/ that obviously are not black in color but if you look closely you notice them moving while the movie plays. They are horizontal and they are about 2 inches apart from top to bottom and there are a bunch of them.. How can this be fixed?
A regular (non picky) viewer would not notice them but and they happen every time a dvd plays.
I am using regular composite cables and I have always wondered about getting those expensive Monster cables. Are they good? and is my issue related to that?
Thanks

[edDV]

Use analog component YPbPr cables from the DVD player to TV and try both interlace and progressive modes. The $19 cable set at Wal-Mart will work fine. You can spend more if you wish.