If you edit the axis labels and the plot is redrawn, the labels will revert to the original text. The only sure way to prevent the labels from being redrawn is to use the Text tool to create your own axis labels and hide the original axis labels using the Axis Options command (choose Axis Options, click Labels, and choose None). This way the labels you create will not be affected when the plot is redrawn.
KaleidaGraph is a thoughtfully designed graphing and data analysis application for research scientists, as well as for those in business and engineering fields. It produces publication-quality graphs, and easily converts the most complex data into a functional display.