  We study the form factors of vector mesons using a covariant fermion field
theory model in $(3+1)$ dimensions. Performing a light-front calculation in the
$q^+ =0$ frame in parallel with a manifestly covariant calculation, we note the
existence of a nonvanishing zero-mode contribution to the light-front current
$J^+$ and find a way of avoiding the zero-mode in the form factor calculations.
Upon choosing the light-front gauge ($\ep^+_{h=\pm}=0$) with circular
polarization and with spin projection $h=\uparrow\downarrow=\pm$, only the
helicity zero to zero matrix element of the plus current receives zero-mode
contributions. Therefore, one can obtain the exact light-front solution of the
form factors using only the valence contribution if only the helicity
components, $(h'h)=(++),(+-)$, and $(+0)$, are used. We also compare our
results obtained from the light-front gauge in the light-front helicity basis
(i.e. $h=\pm,0$) with those obtained from the non-LF gauge in the instant form
linear polarization basis (i.e. $h=x,y,z$) where the zero-mode contributions to
the form factors are unavoidable.
