Delays in starting a radio stream.

[simbun]

If you're playing to the BubbleUPnP local renderer do they play immediately? I've tested your playlist here and through the local renderer all the BBC stations play immediately.
I haven't tested them all but most of the others play with a small delay except [JFM] which produces 'NetworkSource: stream error response HTTP/1.1 500 Internal Server Error' in the MinimServer log.