Fix for Optimisation of Dr. Flemming Hansen's CPMG data to the 'NS CPMG 2-site star' dispersion model.
Fix for bug #21322, (https://gna.org/bugs/?21322) - 5x Test suite fail for version 3.1.0
Reported for system CentOS 2.6.32-358.18.1.el6.x86_64.
Adjusted pA, dw, kex, chi2.