DVD Player Will Not Played Burned DVD's

This is not only confusing but frustrating. Before I switched from Windows 2000 to XP I could burn avi format on Nero 6 vision. Now I have nero ultra edition using vision express 2. The burner states generic dvd x4max r/rw + cd-r rom. I am burning on dvd+r 8x and have a samsung 1 year old dvd stand alone that holds 5 disc's. I have burned in every format from avi to mpeg2 and I get "no disc". Should I switch to dvd-r instead? The info in my samsung manual states that the dvd's must have the compact disc logo on the dvd's ... help