No sound on missenger

I am running windows Vista(install 2 week ago)The old web cam would not work
so---
Pick up new Web Cam with a logo that said certified for Windows Vista,XP and
2000.
Every thing works good on the web cam except---When I go live video I have
no sound. I can see my clint and he can see me. I can send a voice clip and
he gets it and he can send me a voice clip and it comes in OK.
I can click voice only and we can talk ok.
(no video)

When I click for VIDEO I see my clint and he can see me,but no sound.
(only voice clips will work)
I run the AUDIO AND VIDEO SETUP wizard many times and it check ok 100%.
I have uninstalled and reinstall messenger many times in the last 10 days.
I have run Window Missenger for many years and this is the first time I
could not make it run.I am running Messenger 8.1.017800.

I put the Web Cam on a computer loaded with XP and it ran at 100% on all test.

Windows Vista I think is my trouble but dont know how to fix it.

--
Loyd