i cant make proper vcd's!!!?

[tjn]

hi, ive been donwloading MPEGS and AVI's for gaes and never thought of puting them on cd till a couple o days ago...... Now i used nero and made a menu and stuff burnt it but then when i came to play it on my dvd player, the beginig of the movie is fine picture is great... but then when u get further along into the movie the picture starts to glitch as well as the sound.... Now i know for a fact that my dvd player plays vcd's but why is this happening can someone help me pls? thnx!!!!