Updating calibration and method reprocess

[BCBC]

Any thoughts on why a calibrator analyzed, updated in the calibration table and saved, would not return the set concentration when analyzed by the method?
Six analytes all at 150ng/ml. One of the six comes up 149.93 ng/ml.

A calibrator is analyzed. Calibration table is updated and method saved. Reprocess the calibration file using the method. 149.93 ng/ml for one of the analytes. 150 ng/ml for the rest. I have seen also 149.99 ng/ml but not 150 ng/ml.

Thank you for any ideas.

[Don_Hilton]

This sounds like it migh be a software issue. You do not say what software you are using or the nature of the calibration (single point curve or multipoint calibration with replacement of a single level...)

[BCBC]

Chemstation. Single point.
Spoke with Agilent and was told it was a Chemstation-Microsoft conflict, problem, issue...something. They didn't know.
Reinstall software was the answer I was told.
Thanks