Follow-up Comment #3, bug #22032 (project relax): The solution in comment #1 is not good - this will cause severe problems in other situations. It would be better to set dw to something other than 0.0. Having it at 0.0 means that all other parameters (apart from R20) are not defined. I.e. they can have any value and will not change the back-calculated R2eff values. This is why it fails. _______________________________________________________ Reply to this item at: <http://gna.org/bugs/?22032> _______________________________________________ Message sent via/by Gna! http://gna.org/