Let's put m>n two nonnegative integers and Gr:=Grass(n,k^m) the grassmanian of the subspaces of dimension n in k^m. We have a natural immersion Gr \subset P({\Lambda}^{n} k^m) and I call C(Gr) \subset {\Lambda}^{n} k^m the affine cone above Gr. 
If we blow-up C(Gr), we always obtain something smotth, but my question is: 
Is the blow-up a crepant resolution of the singularities of C(Gr)?   
In fact the answer is no when n=1 or n=m-1, but what happens in the other cases ?