Robsp is correct. To be even more specific, the stats on the Campaign Summary page run roughly three hours behind 'real time'. Then, the individual campaign and Ad Group pages are updated after the summary page, so they run farther behind.
This is an expected fact-of-life with AdWords, but engineering is working to close the gap.
By the way, if you look at your stats for the date range of 'yeseterday' (or farther back), then you'll see that they match.
AWA
AWA...Any more specifics you care to share at this point (it is a major issue for us)?
Not really anything to add Robsp, sorry. Essentially, it is understood that this delay between stats pages is not at all ideal, and we're working to improve it.
I'm sorry that it makes things difficult to manage, and can certainly appreciate why this is so.
I'll continue to pass this feedback along, too, of course.
AWA