XY chart in Base report doesn't show data

XY chart in Base displays the data in the chart when editing the report in Report Builder but doesn’t show the data in the chart when the report is run. I am using Base v5.1.3.2 in OpenSuse 13.2.

This happens a small embedded HSQLDB test database with a single table when trying to plot values in the range 0-10 against dates, and with a larger MySQL database. It makes no difference whether the data source for the Chart is the Table or an SQL Select query. The problem does not arise with line or bar charts.

Does anyone else have the same problem? Any suggestions welcome.