This ticket is created in reference to http://forum.piwik.org/read.php?2,87669,87926.
I don't know since when the problem occurs. i think it was after an update to 1.7 or 1.7.x. May you are able to infer the update-date from your graph on http://demo.piwik.org as described in the above mentioned post.
the problem also occurs in my own piwik installation.
Keywords: pageviews missing graph data
Attachment: Missing Data on Piwik-Demopage
Attachment: Missing Data on own Project
first of all thank your for your great work. i love piwik and i love being independent of GA.
the context of the appearing bug is still the same. some data are missing, viewable in my last two attachments. the bug occurs in my own project as well as in the piwik-demo page. but the graph look different :-)
i updated from piwik 1.8.2 to 1.9.2 but i'm not quite sure, wether the data was missing before, or not.
we decided to not fix this... if someone contributes a patch it could be great.