Some labels around a pie chart are missing and others appear to be incorrect.
One or more of the pie chart sections is very small. This causes the labels for these sections to overwrite the labels for the following sections.
If a pie graph is the desired chart type, try changing the chart to a 3-D pie. If this does not rectify the issue, change the chart type to a bar or line graph.
To change the chart type, click the Page Options link in the top, right corner of the report to open the Edit page for the report. Click the Customize link for the desired chart to open the Customize Chart page and select a new chart type.