I am running boinc 6.10.21 on Mac snow leopard.

When ever I have boinc started it uses between 8 and 15 KB/s of my network connection. It does this no matter what network settings I choose, or if I am running projects or not. the only way to stop this is to close out boinc (totally kill it).

How do I stop this? it is causing my to hit my Fair Use policy when I am at home, so I can not run boinc over the weekends when I am home (at school I have cable so this is only a nuisance).

Thanks

BOINC is in 2 parts: the client, which is 'hidden', and does all of the work, and the gui, which shows you what the client is doing.

These 2 parts communicate over one of the cpu's ports, and some firewall programs report this as network traffic. This is NOT the same as internet traffic.
You can test for this by running BOINC, but unplugging the phone line from the back of the computer.
If it's just BOINC talk, this will continue.
If it's internet traffic, it will stop.

Let us know what happens.

Good test idea, I tried it by turning off my wireless card and it was still showing up on Apple's activity monitor (same thing as Windows task manager.

so you think it is the two parts of Boinc talking to each other?

Yes.
The manager (gui) part, displays a list of all tasks being processed by the client.
It refreshes this list once per second, so there's a lot of 'talk' between the 2 parts. The more tasks, the more talk.