If the "Generate members" dialog is open in the Designer and you change the selected module in the Editor, when you return to the dialog its title is not updated with the name of the currently selected module.
I don't know if I understood your answer well (although I think I did) but that's exactly the "problem".
If I select a different module, the members should be created in this one and... and I realize now, while I'm writing, that it wouldn't be enough to update the title but the whole dialog.