Windows Live messenger won't allow cam viewing

[Pozy]

My windows live messenger IM feature is update and working fine. My web cam allows others to view me. However the other person that I want to view is having problems letting me view them. Every time they send an invite for me to view their web cam, a message appears under the invite immediately that they canceled the invite..they are saying that the install of their webcam is correct, however it ask them to update to the newest version of windows live messenger..when they did this..it still didn't work and they couldn't even view themselves from their cam. Could it be a firewall problem for them of just a step they are missing? My friend is very frustrated..what advise can I give them?