Bitcoiner has some DNS problems that affect only some people (and only sometimes). I'm not really sure how to solve that. However it should work if you add it to theetc/hosts file.
EDIT:
If you have problems with bitcoiner.net not resolving, try adding line:
78.47.132.146 bitcoiner.net
to theetc/hosts (Linux) or C:\Windows\system32\drivers\etc\hosts (Windows) file.