Two thoughts, neither of which deals with sound.
Reading post #3, there appears to be issues with Windows itself.
Go here
Black Viper's Windows Vista Service Pack 2 Service Configurations | Black Viper | www.blackviper.com
and click on column visibility. I clicked on all the items I did not want to see so I was left with only a few columns. (see attachment)
Check that the Service has the proper name, and that it is set to what it should be.
Second, please post a speedtest so we can see what sort of download speeds you get on wireless. If the speeds are low, sound can be distorted.
I assume that if you download what you want to play and play it on the computer, rather than streaming from the internet, it plays correctly.