Recently, hourly rates are generally in the 40-60Mb area, sometimes closer to 80. A few months ago, I rarely broke 40. Rates were usually in the 30Mb range. I'm monitoring the router. There is currently only one PC running with two browsers - Opera with about 10 tabs and Seamonkey with three windows of about 15-20 tabs each. That may sound like a lot, but it's only for convenience. Most of the sites are static; discussion boards like this for the most part. They don't load/reload without my asking them to. One of the windows has several Google News pages open that do auto-reload, but I have disabled them for some of this testing.
I thought I had a ghost copy of Networx running somewhere that was causing the readings to double up. I've had that happen before and could see two instances under Task Manager. I haven't been able to find anything there lately, nor any of the other places I could think of to check.
I took everything off line earlier today, set Networx Speed Meter to 0 and waited until the top of an hour so the hourly Usage Stats would be clean. Then I did two upload/download auto tests on testmy.net with each download test running about 2.5 - 2.6 Mb and each upload test running a little less than 500Kb. At the end of those two tests, both the Speed Meter and the Hourly stats showed roughly 5.3Mb or so of traffic.
I can take both Opera and SeaMonkey offline by means of a 'Work Offline" option in them. When I do that, very little traffic registers -- in the Kb figures per hour. I figure that's a couple of desktop widgets I have that check time and weather. When Windows Update or MS Security Essentials update themselves, you can clearly see the traffic spikes.
With the accuracy of Networx more or less confirmed by that test, I more confused than ever as to how my usage apparently doubled recently with no change in browsing habits.