I just bought and installed wavelab 8.0.1 on osx 10.8.3
Once using the external plugin render comes out with some sound errors both in 32 and 64 bits, the erros/noise come in, stay for some seconds and go away. And this happend 4-5 times in a song.
Turning the external plugin off all renders just fine.
I remember there was some problem in WL7 but it got fixed.