In Nero, it will convert mp3s back to standard audio tracks when copying back to a CD.
Does abcde or grip do that?
abcde and grip are CD audio rippers similar in concept to windows ExactAudioCopy and CDEX. Nero is a cd burning program which contains a decoder to convert the compressed audio to standard CD audio so that it can be properly burned. Linux has many simialr CD burning programs, one of which is K3b (included in Knoppix) and yes it can convert from MP3 to WAV or OGG to WAV on the fly.
I hope this helps.
James