Windows Live Mesenger Sound Problem With Vista

This problem started when I upgraded to Vista Home Premium. When making a video call, the person I call can hear me, but I cannot hear them. I've checked the audio setup under Tools in Windows Live Messenger and it will not let me raise the audio levels for my speakers. I can hear a sound when I push the Play Sounds button and the speakers work for all other applications. I've checked Sounds in Control Panel and it appears to be set up correctly.