Windows or Mac?

Oops, sorry Seanyboy -- windows!

I always forget that.

I'm on a mac, and if you were too I'd chime in with how good the Nicecast app is. Instead, I can only wish you good luck.

Is it just that you prefer iTunes, Miko, or have you had problems using Winamp?

Yes, Winamp often crashed my computer, and apparently I don't have enough RAM to run Shoutcast with it without buffering problems.

Or something.

You might try using an older version of Winamp. 2.5 is one of my favorite vintages--it's got a playlist editor, and not much else, so if you want sophisticated library management or smart playlists or whatnot, this solution might not be for you. Do the minimal install of this old Winamp, then use the latest version of the Shoutcast plugin. (Alternately, you might try using the newest Winamp version, but doing the minimum possible installation.)

There's a bunch of stuff that you could change in the Winamp settings, too, to make it less RAM-/processor-intensive, so that it runs better on an older/slower computer. I've had a lot of practice with that kind of thing--hit me up via email or irc sometime, if you want to pursue that route.