We consider the following stochastic partial differential equation, Potential Anal. 28 (2008), no. 2, 139-162]. We show that the strong solutions constructed there are 'locally of compact support'. Using this notion,we define the mild solutions of the above equation and show the equivalence between strong and mild solutions in the multi Hilbertian space S ′ . We show uniqueness of solutions in the case when ψ is smooth via the 'monotonicity inequality' for (L * , A * ), which is a known criterion for uniqueness. R d ψ(x)δ X(t,x) dx.