error in creating 3d DA

[Randall Mackie]

I've run into a problem with my code where, for a smaller problem, it
bombs out in creating a 3D DA (with error message about the partition being
too fine in the z direction) for the case where np=121, but works fine
for the case np=484.

I would think that the creation of the DA should work fine for the smaller
number of processors as well, but maybe there is a bug in the logic?

Randy