Also, it is correct, if you have your channels set up as www.example.com and someone surfs in on example.com, that user's activity won't be counted on your www channel. I always knock off the www for all my URL channels unless I am using subdomains.
i to am experiencing this weird occurence, I have checked all my channels, but the clicks must coming from a page thats not being accounted for, i have a channel for the site... www.mysite.com = 36 clicks 20 dollars the two pages thats are on that site dont add up to the total of the channel for the site....bizzare