I had to configure a site with up to 50 languages for one of our customers.
I wanted to have siteaccesses like de-DE, de-AT, en-GB, en-US, ...
But eZ Publish (tested in Version 4.4) came up with an error saying that it can't find the module.
This is a known issue by eZ Systems.
Basically you can access the siteaccess with de-DE in the url, but this will access the harddisk folder de_DE, and NOT de-DE.
Think about this fact when you configure your siteaccess the next time.
Have a look at this link for further information: http://issues.ez.no/IssueView.php?Id=14156&activeItem=23
