brotherhood_of_LAN - 12:34 pm on Jun 21, 2010 (gmt 0)

305 kbps

allatpen, is that Kilobytes? If so that is more than enough bandwidth. I think Yahoo voice/skype and the likes use 20KB or less a second.

I use voice chat on there and I've never had a problem. If you are using a laptop and a headset, ensure the headset is plugged in before logging on.
There is also a 'voice setup' process within messenger's options that may help you out.

Sorry about the experience you've had with Y!'s technical support, I think for their free services that support is quite poor.