Make sure that you're in the correct plane (G18 I assume).
After that, the move after the chamfer needs to be atleast as big as the chamfer itself and in the same direction.
Too, are you sure that you need the "-" with the C value.
Though I do not know what control you're using but base on your code, something like this...
HTHCode:G1 Z0 X.5 C.03 Z-.05(THIS MOVE NEEDS TO BE AT LEAST AS BIG AS THE C VALUE) X1.