That SUSE VM is not the only one where I see this. I have a Mandriva install that does the same thing, and my Ubuntu install showed no activity during it's updates, either.
My theory is that Network Meter only sees activity that is generated by Windows, and ignores activity from any of my VMs. One more thing I'm going to try is downloading something while logged in on another profile, then switch to this one while the download continues, to see if Network Meter will only show activity generated on THIS profile, or if it covers Windows completely.
BTW, the "Network" settings of the VMs are either "Intel PRO/1000 MT Desktop (Bridged adapter, Realtek PCIe GBE Family Controller)" or they are "Intel PRO/1000 MT Desktop (NAT)". Neither setting makes a difference...