Problem Created Nested Report Object On Report DataWindow

Hi All
I'm using PB703 Build 10213.

I face a problem creating a Sub-Report Object on an existing Report Data
window.
When ever I try to do this the system crushes.

I also tried to copy an existing sub-report object from another datawindow.
In this case the system does not crush, but all columns on the main
datawindow, having a ddlb edit style, loose the ddlb information. (Even if
you define them again, when you close & reopen the datawindwo, they are
gone)!

Any help appreciated

Thanks In Advance
    Stelios