DUMeter shows unexpected traffic. How do I trace this?

[norbl]

I am seeing unknown download traffic in DUMeter. It is usually around 15kbps and is constant. I don't know how to find out what is causing this.

I've run AdAware and nothing suspicious shows up there. I've also run Security Task Manager. There is nothing suspicious using the CPU.

Windows Updates doesn't seem to be downloading anything either.

Thanks.
Norbert