Maybe someone else know of a quick fix, not me unfortunaley, it is also a while since I used 10.6.8.
At least the audio system works correctly.
Few more questions.
Do you have any extentions in Safari preferences, such as Ad block, Flash block etc, these can stop streaming working? I cannot remember if these extentions were available for Snow Leopard.
Did you use a Proxy server in your network settings that as been disabled by the software upgrade, or have they set one up for you in network settings to use the school network?
Do use a particular station, if so what is it and I will try it on my computer. It may give some pointers to what is stopping on your computer.
and I should have asked this before, can you steam radio from other locations, say at home etc.