Issue In Charts

Hi,

While creating report If I add 2 fields and configure a chart, it works fine. But as i add an additional field in the reports to just display them in the table below the chart. Chart graphs does not count the values and un-group everything & give a scattered chart graph.

Like :

I have added >>

Lead Source = Mark It as Group
Lead Source = Function: count

It gives perfect bar chart showing no of leads as per the leads source.

But as i have added a field:
First Name (Display Field)
Last Name (Display Field)

The graph scattered in to many like Lead source public : 1 , Website : 1 , Self Generated : 1 , Website : 1 , Selfgenerated : 1
instead it should give total value like Self Generated = 3 , website = 2 , Public = 1
& graph should be displayed as before it was doing.

Any solution for this ???

Regards,
Ronak