petsc-dev users, I have pushed a change to the MatSetOption() function. It now takes an additional option PetscTruth flg, that either turns on or turns off the option. The "turn-off" options are removed, like MAT_NOT_SYMMETRIC etc.
Please run make all on PETSc after your next pull. Let petsc-maint at mcs.anl.gov know if you encounter any difficulties Barry