Jed, I get doc errors due to http://petsc.cs.iit.edu/petsc/petsc-release-3.1/rev/34db3f4fbf0b >>>>>>> 106] [107] ! Undefined control sequence. l.4336 dt^{n} = dt_{\text {increment}}*dt^{n-1}*\frac{|| F(u^{n-1}) ||}{||... <<<<<<<<< Reverting the above changest fixes the problem. Can you check on this? Note there is also a spurious '40%' in the change. satish