right, where to start. first off let it be known downloading and burning movies is illegal. now thats out the way. although your movies are in either avi or mpeg they may be encoded using another codec which you must have on your computer to help with recoding process. the most common is the divx codec which can be downloaded free from
http://www.divx.com/divx/?src=toptab_divx_from_/index.php (just click on free trial) once installed you dont have to do anything with it comp recognises it automatically. It is also worth while d/ling a codec called xvid from
http://www.xvidmovies.com/codec/ these should help, if not then i would suggest something is wrong with nero 6 (i had problems and got nero 7) another program to use that i very much recommend is ulead movie suite 4 its very user friendly and touch wood no problems yet with it.