Only one object in export and render

Hi, I have exported a model for the first time and when I view it in a 3d viewer (model x converter) it only shows one of the two objects in the scene. The same happens when I try and render the model in blender, the same object is the only one shown. I cant figure out what I am doing wrong.
Any help appreciated.
many thanks,
Nick

What export settings ?
Did you only have the one object selected and had export selected only in the export settings ?

We have no idea on what your scene is like !! Why have you not supplied your blend file and the exported file for review ?

Hi, I have tried exporting with selection only checked and unchecked but it doesn’t make any difference. The scene is a building and some chairs the chairs are the only objects that are exported, (and rendered). Here is the blend file,tortuguero.blend (875 KB). I couldn’t upload the obj file as it said it was invalid.
thanks,
Nick

here’s a link to the obj file https://drive.google.com/file/d/0Bzulz-YNTLFmcXRmOVN4N19GdE0/view?usp=sharing .
thanks,
Nick

For the building you have changed the object duplication from None to Faces. Change it back.

Exporting this as .obj and importing the .obj back into blender you get:


that’s great, thanks for your help