Lost data for one day

Hello,

I am using piwik for some months and never had problems with it. Great tool!

But today I noticed something weird: The complete statistical data for yesterday is missing.
If I select the date of yesterday, all graphs and information boxes show ‘0’ or ‘No data’. Even the ‘Last visits graph’ shows 0 for this day.

The statistical data for all other days is still there.
By the way, I had visitors yesterday. The last time I looked yesterday, there were about 2000.

Any idea what happened here (so it won’t happen in the future again)?
Is it somehow possible to get that data back?

OK, I was able to re-process the statistics for yesterday after this description:
piwik.org/faq/how-to/#faq_59

So everything is back to normal at the moment.