I’m seeing the same problem. My blog is UTC but stats are being generated based on UTC+3. The graph and the summary table are out of sync. The “Top Posts & Pages” for the day are totalling to the same as the summary table.
Also, the entries for “Top Posts” and “Most Active” on the dashboard are blank, but “Top Searches” is populated.
I’m running WordPress 3.1 and WordPress.com Stats 1.8.1