Problem with 'Expense Barchart' report

[absconditus absconditus]

Hi,

I've just updated to GnuCash 2.6.4. The expenses-over-time report
(Expenses Barchart) does not display the graph if the step size is set
to anything smaller than 'month'. I did not have this problem with the
previous release.

Thanks for all your time and effort. It's highly appreciated.