Hi Thomas !
You�ve probably already tried this but ...
Sometimes I�ve got my doors stuck in a "almost locked and almost closed " position on my Vanagon, with no obvious chance whatsoever to open them, but I found out that a good old fashioned NHL body slam with your sholder hitting near but not on ( that hurts, believe me) the door handle will almost always fix the problem !
Don�t overdo it in "Eric Lindroos style" or you�ll end up with a dented door and/or broken collarbone, Vanagons are tough and heavy :-)
Good luck 

Calle
-88 Vanagon
Mullhyttan, Sweden