"no data" Problem with income and expsnse charts

[Chris Burroughs]

GnuCash 2.0.2 on Ubuntu 7.04. Using an account originally created on
the MS Windows port.

I am unable to make any "income &expense" reports.  I instead receive
a message about their being "no data" and "The selected accounts
contain no data/transactions (or only zeroes) for the selected time
period".  I tried changing various chart options to no avail.
Specifically I confirmed that the time period, currency, and accounts
were correct.

The following do not work as expected:
Expense bar/pie chart
Income bar/pie chart

However, these do:
Cash Flow
Equity Statement
Income/Expenses v Day of Week
Income/Expense Chart

The offending charts work fine if I create a new test file and create
some arbitrary transactions.

Thank you for any help.