Just in case anyone's interested...
Apparently the solver just keeps on going, ad nauseum.
I wanted to experiment with periodic boundary conditions, so I decided to see if the solver could calculate the first few propagating modes of a partially dielectric filled circular waveguide, and then also find the phase and group velocity.
Maybe, being that I'm not a MWS expert, I did something wrong.
Anyway, after watching it get nowhere for three days, I decided to pull the plug.
Regards,
Joe