kpickering

I am suppose to get on SL for a class. I have been on in the last month but now I can't get on. I am using a mac. I have downloaded the installer. Everytime I try to go to my university site it stops at saying "handshake" with network. I am at a public library on my laptop and I have not been having any other issues. Any ideas? I have even recreated an avatar so I could start over, hasn't worked. Help. mommakim