Yeah I ran it on an Ubuntu box next to me same thing, I'm on Windows 7 x64 on my evga 780i.
I'll go check that link.
EDIT: Just turned traffic shaper on pfsense, got a whopping 61ms of uplink buffering, of course I effectively killed Comcast's speedburst, before I got 4.7 mbp/s on upload, now I got 2.0 mbp/s. Not that it really matters because my config is 13200/2200