Archive crippled since Sunday

Since Sunday archiving seems to fail somehow.

Data is collected correctly and also shown for the running day. But on Mondays, looking for the stats of Sunday, something goes really wrong:
Widgets are not shown anymore because of an JSon error or having no data.
In the table piwik_archive_numeric_2009_08 are instead of the usual 38 rows now 38*25. Some rows with name=done have a value of 2.
When i set them to one, the widgets work again, though e.g. “Pages” say “No data for this table.”, which is really bad because we have a report running on them.

Archiving via cron job is not activated, current Piwik version is 0.4.1, yet. Why does this happen? Can i restore the information for pages? And how can i ensure archiving works again?

Drop the affected archive table and increase your PHP memory_limit. This should allow PHP to regenerate the archive table and complete the archiving process.