I am also having this problem because my 'My Documents' folder is redirected to a network share

I was able to work around it by using the launch parameter:
-profiles=C:\DayZ

Which redirects it to a local folder, however I couldn't find this launch parameter documented anywhere, I just happened to stumble across is on someones blog...
http://travis.sarbin.net/2014/01/25/dayz-sa-moving-configuration-profile-files/