Looks good Silvio. I see you have the door panels attached to some thing on each side with a screw it looks like. It is hard to tell from these pictures. My suggestion if you have not already done this. To help the door travel better.
I am not sure what you used to connect the door panels. But do this like the do the real ones and it should work better. connect your doors together and then at each connection you will have a rod that will run in the track.
This should help it run smoother. Of course you want to make sure that the track is completely smooth inside and that the ends of the rods are smooth and beveled.
-Mike