JTB FlexReport 4.1.1 is now available. Check the revision history for details that only affects very few if you already have installed 4.1. If you have not installed 4.1, now might be a good time to upgrade as 4.1.1 is as stable as it can be with several customers already using 4.1 or 4.1.1 and I have even tested that it works on Windows Server 2008. If you you on the other hand have old Excel 2000 consider upgrade Excel or stay with an older version of the graphic reports.
It probably is needed to uninstall the old version before installing this one. To be sure the latest version of the reports are installed rename or delete JTB FlexReport Detailed Reports.mdb and JTB FlexReport Graphic Reports.xls.