Using TWPReportBandsDialog

Hello,
We're using WPReporter and WPTools (4.21) with BCB5.

We've made a model for mail merge. In this model there is some BANDS associated with datasources.

The first time the procedure ReportBandDialog->Execute() is executed there is a exeption. The second time, and after, the procedure is called there's no problems. We've got the dialog form and we can do modifications.

What must I do to avoid this first exeption ?

Inside the form I have a TWPReportBandsDialog with the properties :
AutoActivate = false
DataBase = List of datasources
EditBox = name of a TWPRichText component
ShowFormulas = false
StayOnTop = true
SuperMerge = name of a TWPSuperMerge component
Tag = 0

The menu option for accessing the properties of a band contains this code

TWPReportBandsDialog->Execute()

The error message is :
Le projet a provoqué une classe d'exception EAccessViolation avec le message : Violation d'accès à l'adresse 0070B56C Lecture de l'adresse 00000030. Processus stoppé.

Hello,
Thanks for the files you sent to me. The new files didn't solve the problem but they have shown me where to search the problem. I modified the file WPRepED.pas and I have found that the problem was inside two instructions :
FWPReportBandsDialogForm.Left := Application.MainForm.Left;
FWPReportBandsDialogForm.Top := Application.MainForm.Top + 32;
In fact the pointer Application.MainForm is NULL. This explains why I have a exeption. Most of the windows of my project are developed with WINDEV. C++Builder's forms are used for mail merge with WPTOOLS. The main form isn't a C++Builder's form but a WINDEV form.
I have modified my project and Application.MainForm isn't NULL. Now all works fine.
Thanks a lot for your responses and your help.

Jean-Marie DOPPLER