I use OS 8.6. I have only tried downloading files that end in mp3. There are a couple of applications that they open up in, which also confuses me. I just double click them from LW and they either open up in real player or quicken. I have no control under which one though. I guess the computer just chooses for me, or something. And I always download the ones with the most stars. I have also tried downloading them from people with modem, DSL, T1, T3 (and anything else I might not have mentioned) connections. We have noticed that the ones that will end up playing have an icon next to them in the library as soon as they begin to download, while the ones that won't play have no icon.