moduli spaces of vector bundles

Question

Let $X$ an elliptic curve and $M(r,d)$ the moduli space of S-equivalence of semistable bundles over $X$. I'd like to prove that if $(r,d)= \eta > 1$ then $M(r,d) \simeq Div^{\eta}(X)$, where $Div^{\eta}(X)$ is the Hilbert scheme of effective divisors of degree $\eta$ (it can be identified with the Hilbert scheme Hilb^{0,\eta}(O_X). I've proved that if $(r,d)=1$ then $M(r,d)\simeq Pic^d(X) \simeq X$ but I don't know how to use this result and I don't know how to prove that $X^{\eta} \to Div^{\eta}(X)$ is the geometric quotient of $X^{\eta}$ under the action of the simmetric group. Do you have any hints?