I get a lot of slow connections, but then I also get a few faster one too. Have you tried a lot of different files and types of files and times of day just to test things out? You computer should be fine.

People with fast connects normally are uploading to a lot of other people so their uploads end up almost as slow as people with slower connections. BearShare has the QoS bars and the connection speeds, that helps sometimes. As more people share the network should become faster.