MSN 6.1 Audioproblems but WHY???

Hi, so I'm having audio problems like 50% of the msn comunity. I have
seen tons of posting about this but not even one response that solves
the problem.

Sympton:
I can send messages and we can see each other with webcams. In my
network, in Italy and also with friends in Sweden. But, I can not talk,
with my other computer at home I can talk, even though in the begining I
could not. Then I could talk with a friend in our network, but I
couldn't hear him, we closed the conversation and reopened (without
changing anything) then he could not hear me either. The other week I
could talk with some people (two way) in Sweden, no I don't hear them
and they don't hear me.

I have
1) XP Home Edition
2) MSN Messenger 6.1
3) Webcam
4) Microphone that is connected directly to the soundcard

I have tried
1) The configuration in MSN, works fine
2) All permutations of possible configurations of sound
3) Disabled QoS (even though I don't know what it is)


I can not touch any router since I'm in a LAN (fastweb in italy is a
big LAN 10Mbit) so I can do nothing about UPnP (in advanced settings in
MSN it says that I'm connected against a non UPnP IP-limited NAT)


Please, if someone (expert or miracle maker) solves these problems,
tell me. My e-mail:

Tim