My day job is being a tech support rep for C****st high speed cable internet services - and we are getting a lot of calls from Mac Leopard users. From what I'm seeing - if you connect a Mac Leopard into any home networking device - i.e. your router: everything else on the network will get painfully slow. This includes Windows based PCs and network-attached games such as Xbox and Playstation. Due to this situation a lot of people think it has to be the Internet Service Provider and may think that they have to upgrade to a faster speed-tier. But what this really means is that something in Leopard is producing a lot of error traffic on the home network - which uses up the bandwidth and processing capabilities of the router as well as the host computer.