Yanking by pressing "yy", "yl" etc. does not work. When I press "p", it pastes whatever was previously copied by Command+C instead.
If I do ddup instead of yyp, it works as intended.
In the command line vim, yanking works as intended.
Here's the output of :version:
:version
VIM - Vi IMproved 7.4 (2013 Aug 10, compiled Oct 25 2013 20:05:26)
MacOS X (unix) version
Included patches: 1-52
Thanks,
Anders Schau Knatten