How do you run autohaven.jnlp ? Have you tried "Open with Java Web Start Launcher" after clicking the play button and being prompted for action? That's the default way.
Before you do open Java Control Panel -> Security and put in
- Code: Select all
http://www.havenandhearth.com/
https://www.havenandhearth.com/
into the exceptions list at the bottom
I recommend trying to get the default client running first before trying with a custom client.
report back please