think-cell uses PowerPoint's Master textboxes to enable promote/demote functionality. Under certain circumstances, when a think-cell chart is copied to another presentation, PowerPoint tries to be smart and updates all the Master textboxes to the styles as defined in the Master of the target presentation. If the Master of the target presentation has a bullet defined on the first text level, then PowerPoint enforces this setting on all copied Master textboxes, including the ones that belong to the chart.
think-cell cannot automatically remedy this situation, because the software cannot distinguish between automatic bullets from PowerPoint and bullets that the user enabled on purpose. The problem can be fixed manually:
It is recommended to avoid bullets in the first text level of PowerPoint's Master slide. This way, the problem described can be eliminated. Moreover, even on slides that do not contain any charts, it is usually not desirable to have a bullet on the first text level.