Pivot / centre point stuffed on export

Hi i create a Robot with bones and make a walk cycle for it- it seems all good until i try rotate it in directx when it doesnt rotate around the centre of the robot it rotates around a weird pivot point so it doesn't rotate right. Why is this?

That's hard to tell without

That's hard to tell without data. You could export to text X file, and look where the pivot points end up (it's the translation part of the Frame matrices).
Also, you may want to "reset transform" on the nodes before exporting.
Finally, if you rotate the entire scene (the top-level frame), then you should be aware that the entire scene is centered at the origin, and if the robot is not at the origin, it won't rotate around the center.