Piwik doesn't log at server side

Support & Bugs
1

I have integrated the piwik-Tag into the website.
The JavaScript works fine and when I look at the outgoing HTTP-headers (with LiveHTTPHeaders), the piwik.php tracking script is requested correctly from the browser.
When I request that url manually I get an 1 pixel gif. No script errors or such things.

But when I call the piwik-statistics and -log I cannot find any new visitor.
Strangely this worked yesterday and then the logging suddenly ceased functioning.
What could be the reason? Can I diagnose the problem?

With best regards
Inno

2

I have turned on debuggin in piwik and got the following message:
visitor excluded
But why? I wasn’t logged into the administrative interface - so there is no reason.

With best regards
Inno

3

I have found the reason:
The piwik.js has been copied to a public directory.
I have made an auto update of piwik. Piwik has also updated the piwik.js.
The new piwik.js was not been copied to the public directory - so the visitor loads the wrong piwik.js.

With best regards
Inno