Looks like it wants to connect to a gnome proxy? (dialing home somwhere?)
iirc there has been previous issues with radiotray.
Is it gnome dependent as the glib net app should not wipe out audo streaming.
I tested the cmus app with
it took a coupleof seconds to play but did so with out issue
I also note that radiotray is 'just' front end to sox/play so I tried
play -t mp3 http://icecast3.977music.com/classicrock
Again played perfectly.
I would say that its the spurrious call home to gnome thats the issue and is not hammer related
anyone up for making a systray app for the 'play command that does not all home? lol)