Why can't I receive streaming audio on my system?

I am using Live Meeting to participate in Webcasts put out my Microsoft. It uses the Windows Media Player to broadcast the streaming audio. I am unable to connect to this audio. I get an error stating it can't find the server and to check that I am connected to the network. I have checked all of my players settings, made sure Multicast, UDP, TCP, and HTTP are all checked. My security zone is set at Medium which is the reccomended setting. I can receive streaming audio from radio stations and streaming video with audio via the player. My webcam receives streaming audio just fine, the firewall shows no problems either, nothing is showing as blocked, nor any errors or announcements of a program attempting to access my computer. Just nothing, and the error. I am hoping somebody here will be able to tell me what I need to do to fix this, as it has to be my computer, not the Live Meeting program, as other participants receive the streaming audio without incident. Please suggest ideas, thanks