GQMpeg 
It turns out that mpg123 is better at not-garbling the music than xmms is. It also turns out that GQMpeg is an old, yet adequate GUI front-end to mpg123. (Better playlist handling too.) It still garbles the occasional track (and always when in the background), but stopping/restarting the track has always fixed it thus far. So I created a batch file (called ~/bin/music) which sets the LD_PRELOAD if necessary and then launches GQMpeg.