Month visitor = 0 while week visitor > 0

Hi,

Been using piwik 1.5 for 3 months now. I have 2 domains on the same server being monitor by piwik. I notice graphical inacurency twice now.
In one case, for domain A, the month view for the total in Novembrer shows zero, while if I look at the weekly view (as well as the daily view), for each period covering the month of November, I see the values > 0 !!!

The other case is for domain B, for the last week in November (28/11 - 4/12) it shows zero, while if I look at the day to day view, all data are > 0 !!!

Is there a way to have the data being recalculate so the roll-up data data base will correct itself ???

How do you explain this situation … ?

Please moderator I have by mistake posted this question in the suggestion forum. Please remove the later.

Merci

Maxime