do you have VM on? are you using a dial-up (56k) connection? answer those questions. VM will decrease the performance of just about every and any streaming media, b/c the hd has to be access twice as much, for the media, and for the swap disk. as for internet media, the same thing holds, if your computer is using VM, then the media player is most likely using the hard drive as a buffer, so every 30 seconds or so it has to clear out the buffer, hence, run the hard drive, slowing stuff down, when using the MacOS, you cannot go wrong with more memory.