export\import problems


I have a problem with exporting a file.

I wanna export a file with 6000 vertices to .x But when i wanna import the .x file in Blender than i get this error:

Blender.Scene.GetCurent<> instead.
Traceback (most recent call>:
File <’‘string’’>, line 305, in_my callback
File <’‘string’’>, line 82, in import
File <’‘string’’>, line 160, in writeVertices
ValueError: invalid literal for fload<>:1.#QNAN0

And Blender shut down to.

If i try to export the file to .3ds it import just fine. But when it is imported i dont see the mesh.

I hope you can help me with those problems. thank you