Column names in Piwik Export Files (TSV Excel) is not correct.
Piwik 1.7.1 (possible other versions also)
TSV Excel report (possible other reports)
Steps to reproduce:
1.) Goto Visitors > Overview
2.) Select “month” in period selection (IMPORTANT)
3.) Click on save icon and select TSV Excel and download report
The report will show more Unique outlinks than outlinks. It also shows more Unique Pageviews than Downloads which is very uncommon. [Of course there are a lot of 0 in columns because piwik got new metrics in 1.7]
Can be reproduced here: http://demo.piwik.org/index.php?module=API&method=API.get&format=TSV&idSite=7&period=month&date=2009-10-01,2012-03-31&expanded=1&includeInnerNodes=1&translateColumnNames=1&language=en&filter_limit=100&token_auth=anonymous
There seems to be a lot more columns that are switched.