Voice Problems (server related?)

I need help with a problem. I am running an HP Media Center PC with 2.8 GHz Pentium-D, 2 GHz of RAM. I have had no performance problems with SL whatsoever. In fact, SL seems to crash for me less than for many other people. I have a cable modem, a 2Wire home networking router and an AirPort hub, running through a LinkSys wireless adapter. According to the LinkSys monitor, I am getting 54 Mbps bandwidth. I have tested my VOIP bandwidth at TestyourVoip.com and got a signal rating of 4.4 out of 5 to San Jose and back from the East Coast, with no packet loss.

Here is my problem. When I connect to SL's voice server, the signal from my voice mic begins to break up at regular intervals, like I am talking through a fan. If I disconnect from the Voice server, it works perfectly. And, of course, this doesn't always happen, just sometimes. I have made sure to enable all appropriate programs and ports in my firewall and router. I'm just not sure what else to do. Please help!

Well I have found that the problem only happens on my end. It sounds fine in SL. So, even though it is annoying, I can live with it. So...Thanks for all of you who were going to respond to this.