Ok, so I'll explain the problem and then all the things I have tried.
Problem: 2 people have the Quickcam Pro 4000's. We'll call the two people John and Jane to make it easy!!!
They are connecting by AIM to video chat. John can see and hear Jane. Jane can see John but not hear him.
Solutions I've tried: 1) checked all the volume levels on Jane's PC
2) reinstalled QuickCam software on Jane's PC
3) checked sound options in AIM
All sounds on Jane's PC work (ex: windows media player, windows startup sounds, IE, etc). You can even hear the buddies on AIM login/logoff.
So my question is, why can't Jane here John? Thanks for your help!