@Chouby
That's correct. It works when the language code is hidden for the default language (mysite.com).
As soon as I turn on the language code, it fails (mysite.com/nl turns into mysite.com/nl/nl).
My second and third language installed work perfectly now.
My permalinks are: /%year%/%monthnum%/%postname%/
But is also occurs when it's just: /%postname%/
I use the development version.
Hope this helps.
Regards