I making an assumption youre listening to it on broadband?
Although you'd expect the occasional drop off on dial up suppose in theory its not supposed to happen on broadband. My own experience is you still get that buffer thing trying to catch up even on the broadband. It does seem to depend on the station your listening to and if theres heavy net traffic at the time. So much for lightening speed accesss on broadband hmmmmm.
tis probably a busy day on tinterwebby thing. The trouble with broadband is it's only fast(ish) to the exchange where it plugs into the whole big mish mash of the internet. After that it can be fast or slow depending on how many bits of the internet are broken that day
here at work we have a blisteringly fast gigabit network backbone, but there are still days when accessing the internet is slower than a slow thing.