  The electromagnetic current of spin-1 composite particles does not transform
properly under rotations if only the valence contribution is considered in the
light-front model. In particular, the plus component of the current, evaluated
only for the valence component of the wave function, in the Drell-Yan frame
violates rotational symmetry, which does not allow a unique calculation of the
electromagnetic form-factors. The prescription suggested by Grach and
Kondratyuk [Sov. J. Nucl. Phys. 38, 198 (1984)] to extract the form factors
from the plus component of the current, eliminates contributions from pair
diagrams or zero modes, which if not evaluated properly cause the violation of
the rotational symmetry. We address this problem in an analytical and covariant
model of a spin-1 composite particle.
