How to shrink groupHeader or to hide a xrtable in the groupHeader - don't work

Hello
I have a question to a problem with the report.

In this report i have two groupHeaders, detail-data and two groupFooter-areas. The user have the option to start the report with or without detail-data. My problem is, if i start the report without the detail-data. I suppress in some "BeforePrint"-events the print-process -
a) for the detail-area
b) for the xrTable - is the header for the detail-area.
This works fine, but i can't delete the empty space from the xrTableHeader (for the detail) - see the attached image.

I have tried some different solutions (found in this support-forum)
1) i set all table-cells from the xrTableHeader to "canShrink" = true
2) i set for all table-cells the BeforePrint-event, and do also a "e.Cancel=true"
3) i try to change the GroupHeader.HeightF
4) i set in the xrTable-BeforePrint - event the "e.Cancel =true"

But nothing of this steps are working 100-% fine - it works do hide the detail-data, and the xrTableHeader.............but the there is always the empty place in the report from the xrTableHeader.

Please have you an other clue for my problem ???
I give to you in a second post the report-source.

Many thanks in advance for your help & best regards
Michael