Shoutcast streams being opened with WMP

[Grapes29]

Using Windows XP and Winamp 5.52

Looked through the existing troubleshooting topics and can't seem to find something specific to my problem.

When I click on "tune in" Windows Media Player opens (and subsequently tells me it can't play the file. Thanks).

I've associated .pls's (and all audio for that matter) with Winamp. Why isn't Winamp opening and playing the stream?