you've got N-Gons!
you need to add in edges round your 'holes' to stop them from closing. (this is a limitation of the OBJ format) \
split the faces down into Quads, making sure you work round the holes in the mesh you want linking the edge of the hole to the edge of the face (point to point). that will fix your woes. do the same for the silver section. (looks like the gold is closing over the silver you see.)
if you have a renderosity account, I showed how to fix it here -
http://www.renderosity.com/mod/forum...essage_1896641
