Nope, that can't be the issue.
I'm irritated by the words "all bones" - normally you switch to object mode, and select the armature as it is called in blender as an object and you select the model as an object.
Maybe, you have to select the model first and then, with shift hold, the armature...
Sorry, that's what I meant.
You can send me the blend file, if you want that I have a closer look at it. (Don't include the skin or a highpoly mesh to keep the size small.)
Thanks for the offer, unfortunately the mesh is rather high-poly, ~15000 Vertices. I'm going to try to export a different animated model from blender and then come back and report what happened. If it works, then it is probably just the MakeHuman-Model which causes trouble, if I can't get a simple animated model exported, then either my Blender/MED has some sort of a bug or I'm just to stupid to get this done xD
Thanks for the help so far!
Alan