Thanks for all of the info everyone. We need to know a couple of things:

1) are you running as an UltraPeer when you see these CPU percentages (you can tell you're an UltraPeer if you have connections labelled as "leaf")

2) how many files are you sharing? do you see CPU usage go up if you share more files or down if you share less?

3) how many connections are you maintaining (in the connections tab)?

4) how fast is your web connection?

5) how fast is your machine (CPU)?

Thanks very much.