It seems like the same thing happens to "ap" (Asia/Pacific Region) on demo.piwik.org so there are three "unknown" sections. (ap is also missing a flag)
Thanks for the report. Since Europe, Asia/Pacific are not countries, we shouldn't detect them as countries. we could just detect them as Europe / Asia in the "Continent" report.
This should be solved with the GeoIP2 migration as there are no more EU and AP countries in GeoIP2.
Right. This won't happen for new reports after the migration...