Report Designer hangs

I am trying to edit an existing report.
This sequence causes Toad DataPoint to hang:
Open report.
Select TableCell.
Update Binding.

The user interface freezes.
Task Manager shows no CPU is being used.
I have to kill the process and restart.
And, I am unable to save the change.

Is DataPoint displaying a pop-up window that is not displayed?
Is DataPoint running a query and it hangs?