Reports (Chart and Graph)

[smada46 at wbaccess.net]

I have been trying to get reports with bar chart for my individual utility expenses.  My account tree is set up with Expenses - Utilities - Elec (etc).  When I select the expense bar chart report and select the child account Utilities, I get a bar chart with total utility costs per month.  But, when I go one child level lower (Elec for example) I get an error report as follows:  Report error: an error occurred while running the report.  I have tried this with each one of the individual child accounts under utilities with the same error.  Is there a setting I am missing?  I want to keep the account tree as it is because I also like to have a total Utilities monthly chart as well as a monthly individual utility chart.  Can you help?