Error Bars in Numbers

Has anyone figured out a way to change the value of the error bars within a series? When i assign an error bar value to a specific data point in a series, it changes the value of that data point for the entire series. This is not the correct way to assign error values to data. Each data point should get its own value but there is no choice but to select the whole series. Ive read the user manual, it doesn't appear to help. This is a pretty serious oversight as it basically renders numbers useless for statistical data. Thanks, any help is appreciated.