We are currently using Aspose 184.108.40.206 (we hope to move up to Aspose 7 in the next 6 months) and when we create a chart in the xlsx format and then it is opened in Excel 2007 the right edge of the chart's Chart Area is truncated. Sometimes this truncation will actually cut off part of the plot area. It appears like the area is actually too wide for the "frame" in which it is drawn. I can manually resize the Chart Area in Excel to make it less narrow and then the chart will appear fine. (Being able to manually resize the chart area seemed odd too. Especially since the chart is in its own tab.)
If the same xlsx file is opened in Excel 2010 it works fine and if we generate an xls file it works fine.
I have attached a zip file containing a Java method which will create a workbook with a sheet and a chart. The zip also includes an xlsx file generated by the code.