The player is most likely experiencing network congestion. This means that there is not enough available space on the network to stream the selected file from your ISP (Internet Service Provider) to your computer.

There are many reasons why this can occur, but generally this will be caused either by congestion (too many users sharing ISP resources) or because the stream being played is bigger than your home Internet connection can manage.

Windows Media Player buffers several seconds of data before starting to play the stream, and when network congestion occurs will use the data in the buffer until the stream is restored. If the contents of the buffer are used up before this happens, the video will pause and Media Player will re-buffer before playing again. This cycle will continue until network conditions improve.

There are a number of things you can do to ensure that this effect is minimised:

1. For 56k users, it can occasionally help to drop the connection and redial.

2. For all users, ensure that the bandwidth of the stream you are trying to view is less than the bandwidth of your Internet connection. If you are unsure, use the 'Which video should I view?' link beside the video window (as shown below) or click here.

3. Make sure that there are no other applications or Internet Explorer instances that might be using up your bandwidth.

4. Increase the size of the Media Player buffer (see How do I increase the size of the buffer in Windows Media Player?).