[iBook] Plantronics Headset

[Rebecca Hoffman]

I've got a G3 IceBook running 10.3.9. I've recently discovered Skype 
and have gotten a Plantronics Headset to use with it.

The problem is, I can't get my internal speakers to turn off. I go to 
System Preferences and select the headset for both audio output and 
input. The headset mike works, but the other person's voice continues 
to come out of the iBook's internal speaker instead of the headphones. 
This is a problem, since the headset mike picks up the sound from the 
speakers and the person I'm talking to hears a disturbing echo of 
himself.

Any suggestions, oh wise ones?

Rebecca