"jumping " or buffering is really about the download speed of your broadband connection . Mine is poor rarely getting up to 1mb but the radio works . Some stations with high audio quality can cause problems as they require higher download speeds to get the quality of course.
There is also a licencing/copyright issue and I have noticed that live sport is not available on BBC 4 and 5 via the Internet .
My radio is a Tevion it works fine but the interface is clumsy and there are only 10 presets .