I was listening to several Shoutcast stations (WolfFM, Monkey Radio and Radio FG). France, in particular, has a tendancy to get interupted, so I thought that I would increase the buffer size (tried it both using native MP3 decoder as well as in Shibatch mpeg123 plugin). Entering a nice round number like, oh, 4000 appears to be a recipe for death. Winamp would only generate "no valid frame" errors. I stopped and started Winamp a number of times and tried switching decoders (back and forth between Shibatch and native). No difference. I tried all of the above channels. No difference.

Breaking out my calculator, I multiplied 256 a bunch of times until I got 4096. Entered that into both decoders, restarted Winamp, and now it works fine.

So, it would appear that unless you enter the proper number, you get an invalid frame error. Which leads me to the following suggestions:
* for native Winamp decoder, you should have a pull down menu that only lets you select valid numbers (say from 64k to 8192).
* for third party decoders, since you can't control their interface, you should have a clearer error message that explains to the user what numbers they should use.