when you don't see a tool create wave files it is called "on the fly" encoding. It is a faster way, but it doesn't show you when there is something wrong with the mp3's. WHen it can detect there is somethign wrong with the mp3, the burning will stop and you loose a cd-r.
I don't think it will happen a lott but it is possible.
Back to NEro;
WHen you use NEROSTARTsmart you will have to use ADD and look for the mp3's. Like in the picture.