Good questions as ever Tony...

These same streams do not pause when you are listening to them in WinAmp on the PC? In other words, you're sure it's the Receiver's fault and not just a crappy internet server or a crappy internet connection?

Correct, they all play back fine in WinAmp (including the stream that is sourced locally from my digital radio tuner).

Does it happen all the time or just once in a while? In other words, can you reproduce it reliably?

Yes is can be repro'd 100%. It varies though, with the pauses coming every 2-20 seconds apart, the gaps between pauses seem fairly random. The pauses happen on every stream I have tried.

Do regular MP3s play back OK on the Receiver, in other words, are you sure this problem is only with the streams from the 'net?

Yes, everything but streams play fine. In fact if I take my MP2 stream from my tuner, capture it to disk, change the extension to MP3, import it into the Receiver manager then it plays fine (if a little slow as it is a 48khz stream).

Are there really only two people that this problem occurs with ?

It couldn't be anything as silly as 50Hz mains power vs. 60Hz could it (I'm in the UK on 50Hz). Sounds unlikely I know ;-)