An hour ago I had 89 clicks for the day with $18.17 in revenue. Just a moment ago I checked, and I have 93 clicks and 17.86 in revenue... what the hell...
Chances are that some of those clicks were flagged as potentially fradulent. Are you looking at the same report? Sometimes I have found that the summary page (when you first log into your account) does not always sync up with the advanced reports I run. Hope this helps.