SW2013 x64, SP3.0

In performing a thermal study of a heat sink, I set up a simplified model with one heat power and one convection coefficient.

I am running the model at several convection coefficients and leaving the heat power the same.

The first time I ran the study, it completed in several seconds. Each time I edited the convection coefficient, it has taken longer to complete the study. Now that I'm on the 6th run, it takes about 5 min to run. Even right-clicking on the thermal load requires a minute or so wait time till SW responds (it shows the swirling ring icon in the meantime).

What is going on?? Is SW somehow saving previous run information? Do I need to be deleting previous results files??

I have saved everything locally, so its not working over the network, as far as I know.

Any ideas?

Thanks,

=stan