Exporting Textures to ply - NOT WORKING????

Hello,

I created a small model with blender and added a texture. When I now export this model the texture sometimes is on the inside of the object (the face normals are pointing outwards though) or does not appear at all.
I tried to export to ply and to obj.

Does anyone have an idea what I’m doing wrong?
Btw. I’m using Blender 2.5.

Greetings