I wish it was because of my super-duper optimisation skills, but it's not. Basically I "cocked up".

The F77 code looks for model files within a <i>z</i> (redshift) of 0.005. I misread this as 0.05. What is happening is the F77 code just says - "I can't do this" and exits nicely.

As one of the models is at <i>z</i> 0.05 and 107 galaxies are at this <i>z</i> I've moved them to the front of the queue.

I'll spent 10 minutes in corner with the "Stupid Kevin" hat on as penance - then I'll fix it.