Rated 4 out of 5 stars
I can confirm what Reiner told on April 14, 2015:
I tried to import from UTF-8 VCF file, but all umlauts got worse. Simple workaround for me: copy all files into a single VCF, convert this to ISO-8859-1 and import from this single file --> worked.
But it's not the right way to simply workaround existing UTF-8 coded files...