Has WP made an official statement about the end of day reset problem with the stats?
Last week (Thursday by most accounts), the daily stats started resetting at UTC+2 (or 3) hours as opposed to using the settings in the blog.
I don't know how widespread it is, but a couple of other bloggers I've contacted have this problem and it's been discussed in the forums.
Right now, the daily stats and the graphs are out of synch. The graphs seem to be obeying the timezone settings, while the stats are not.
Has the root of the problem been identified and is a solution on the way?