Voice problem MSN Messenger 7.5

Hi all,
When having a video conference, my friend and I cannot hear eachother. When
we have a voice conference, we can hear eachother. I cannot move the
sliders next to the webcam images - they are set to the bottom and can't be
moved. I can move the sliders in a voice conversation.

Any ideas? We both use MSN Messenger 7.5. We know that the mikes and
webcams work, but we can't see and speak to eachother - it's either one or
the other.

Any help gratefully received.
Thanks,
Steve


.