Piwik campaign-Data inconsistent (no replies)

Hello,

since a couple of months our piwik-archiving-cron-job failed due to php-memory-issues.

Today I fixed the memory-setup and archiving works flawlessly.

But I still have problems with campaign-reports. The data is wrong:

report 1:
The Campaign-report (Referrers->Campaigns) for the date-range year 2014 shows 19 different campaigns with 1200 visits total.

report 2:
Now, if I change the date-range to <<From 2014-01-01 to 2014-12-30>> Piwik shows 19 different campaigns with 1199 visits total.

report 3:
If I change the date-range to <<From 2014-12-31 to 2014-12-31>> Piwik reports exactly one visit from one campaign. This is the one visit report 1 has more than report 2.

report 4:
If I change the date-range to <<From 2014-01-01 to 2014-12-31>> Piwik reports "There is no data for this report."

report 5:
If I change the date-range to <<From 2014-01-01 to 2015-01-21>> Piwik shows 6 different campaigns with a total of 43 visits.

Report 1, report 2 and report 3 are consistent.

Report 4 and report 1 should provide the same result.

Report 5 should show more campaigns and more total visits than report 1 or report 2.

Any idea, where the problem might be?

Regards, Rikky