Can't hear audio from other sources when WL7 is running

I can’t hear audio from any other source (Winamp, YouTube) when Wavelab 7 is running. Why would this happen, and how to fix it?

Wavelab needs your driver in order to playback your audio, and keeps other apps from stealing it by default.

A useful function is under Audio Steaming Settings check the box Release driver When Application is in Background. This means that if you maximize itunes or another program that requires your driver, WL will release it to the other program while it is maximized.

Keep in mind that anytime you maximize another program with this option checked, you won’t be able to hear WL’s output until you maximize WL again.

I still don’t understand why this is happening on Core Audio. I can listen to various apps simultaneously while running a Logic project in the background.