I can't add much to the knowledge on networking; I can however add my agreement that Leopard is less tolerant of crappy connections. On my way to Iraq I had to stop in Kuwait for 3 weeks. They had free internet and all my windows buddies were cruising along (Slowly) with the crappy internet, but when I connected some pages worked, some did not. It seemed to clear up at about 2 am when no one was on the net and I had a more stable connection. Is it possible that you have a slow/crappy connection or a slowly dying router?