Reply to Traktor Sound Question

Hiya,

Whenever I use the Asio drivers in traktor, i can't hear any sound coming out of my laptop speakers.
If i have headphones plugged in, or external speakers plugged into the 3.5 jack, it works fine.
I'm wondering why this is, and if there's any way to fix it because whenever i want to show something really quick to somebody, i always have to ask them to plug in their headphones or i have to find some speakers. But if i'm on a bus or something, i won't always have external speakers.

help?