I am plotting graphs with custom error bars in Excel 2003. If I change the
size of the error bars (by changing the cells that the custom error bars
refer to), the error bar patterns sometimes, but not always, change by
themselves. For example, I normally set the error bars to medium line
thickness and with a cap on the ends, but when I change the source data for
the error bars, some of them change to a different line thickness and/or no
cap on the ends. They are not even consistent within the same series. About
2-5 out of 12 error bars in each graph (not always the same 2-5) get changed
each time. I know how to change the error bar settings, but it's a pain
having to change them back all the time when Excel changes them by itself.

Have I missed a setting somewhere - does Excel automatically change the
error bar pattern depending on the size of the error bar? Is there a way to
turn this off? Or is it a bug in the program?

Thanks.