universal remote + panasonic viera

first off new here.well been searching all night and still cant find an answer.the problem i am having is that i bought th tv from a cousin of mine and he didnt have the remote for it,therefore i went and bought a universal remote the GE 24944 to be exact(cheap and convenient so i thought).well now i can get the remote to connect to tv but the problem i'm having is i'm only receiving 13 channels and the rest keep showing with no signal.i've tried coding the cbl/sat button to no avail.i can press the menu and it'll pull up the menu bar but won't let me do anything as far a settings.so what could be my problem ? also i'm using cox cable with no digi box but i dnt see how that would be a problem when i can hook cord to previous tv and channels will show fine.thanks for any help in advance

thanks