If you notice dashes in the place of the numbers in your adCenter statistics reports, then no need to worry.
In a WebmasterWorld thread, adCenterEU explained that the dashes represent that there was a timeout failure between the reporting and the database.
All you need to do is refresh the page and hopefully those pesky little dashes will be replaced by real numbers.
If that's in the interface then refresh your page a couple of times.
Sometimes, for what ever reason, there may be a break in the connection to the DB so instead of a timeout message you'll see some dashes.
Try refreshing the page and let me know...
Forum discussion WebmasterWorld.