The server does not like streamripper. If you connect with the default "User-Agent “Streamripper/1.x” header it is closing the connection. You can overwrite this with the -u option:
streamripper http://ice6.somafm.com/groovesalad-256-mp3 -u myfakeagent
Connecting...
stream: Groove Salad: a nicely chilled plate of ambient beats and grooves. [SomaFM]
server name: SHOUTcast/Linux v1.9.5
declared bitrate: 256
meta interval: 16000
^Ckipping... ] Skylab - Next 173kb]
shutting down
bye..