Ubuntu :: 10.10 Using Continuous 8.6kb/s Network Download?

I've installed Ubuntu 10.10 64 bit (I am an experienced Linux user here), installed a few extras like docky, zeitgeist, added my Ubuntu one account (I don't synchronise much at all, about 100kb max), my twitter account using Gwibber, but nothing much else. I also mount a few smbfs shares in my fstab file at bootup. About the only other program that uses the net that I can think of is running would be rabbitvcs, but I can't imagine that will keep downloading if I am not doing anything.I noticed that when opening system monitor, it is continuously downloading 8.6kb/sec, even if I am doing absolutely nothing. It gets to the point that after an hour or so of use, 100mb or more has downloaded, but what for??

I tried a Googling a few commands to figure out what is eating up network download bandwidth, such as "netstat -p" and "lsof | grep tcp", to try to figure out what is downloading so much at a constant rate, but I can't seem to find the process.I have tried disabling stuff one after the other:

I disconnected my Ubuntu one account

I removed my Twitter account from gwibber

I terminated zeitgeist-daemon

I terminated all desktop-couch related processes

I disconnected all my smbfs drives

But it is still downloading 8.6kb/sec, steadily. This is wasting a lot of bandwidth during the day, and I am not sure what is causing it.

p.s. it is only doing downloading, never uploading.