Hello,

There's really no way to get around the quality issues in Cubase when you are slowing down the tempo. Cubase 4 has an improved algorithm, but if you slow the audio down too much, it's still not going to sound that great.

Now Wavelab 6 has an amazing time stretching feature. It actually sounds pretty good when you slow down the audio considerably. It does take quit a while to process. Unfortunately that would mean spending more money, and you'd have to import the audio into Wavelab, time shift it, and the export it and import it back into Cubase.