google-earth: error code 29

I've just installed google earth from ports. It looks like it is in fact the linux version packaged up. It starts fine, but then I get this message:

Google Earth Error

Google Earth detected an error while trying to authenticate. Please check the following:
- your network connection (can you get to
- your firewall settings
(are you blocking /usr/lib/googleearth/googleearth-bin?)

Error code: 29
For more information, visit:

[OK button]

Net connections are fine, just for some reason this program doesn't know it's allowed to connect, any ideas?