I used mymp3 to record some music off youtube and converted them to mp3 files. The sound quality is quite good and plays fine on the pc. But when I used nero to burn them on to a cdr, some tracks go blank/mute about half way through the song, but a few play fine all the way through. I use the "what you hear" option to record.
I do the same using Audacity click here and never have any problems, you could give it a try. Only other thing I can think of is a problem while burning, try CDBurnerXP (works with Vista as well). click here