I just tested your code and everything is running fine. I move the player about and the digits change as expected.

I don't think this part of your script is causing you the problem. Make sure the player is set up properly and that the player pointer is initialized properly.

Panels should be able to display vectors, variables and defines. I've never had a case where i couldn't display one of them.

Apart from that i can't think why you are getting a constant 0.