Does anyone know why or a fix for when you append or add mesh from a new version of blender into an old version, its all wireframe?
basically,
When append mesh from 2.71 into 2.59, the mesh loses all its faces.
The mesh system was completely replaced at one point between those versions (to a new system with better quality data along with Ngon support), so it is highly possible that you will lose some of your data when backporting to a version with the old system.
This isn’t a BGE bug by any means, what you might try to do is get a version of 2.63 (the first release with Bmesh support), and use it as an interim step in the backporting process (though I don’t know why you would want to use 2.59 as many people regard 2.69 as the best recent release for the BGE).