When placing text, clicking on the image should set the coordinates in the text dialog as long as the dialog is open. Moving the location for the text block being placed to that location.
This is a problem when the default coordinate position is not currently visible on the image because the text block is not visible either. So the user can't move it or even know that it's there. And it's ridiculous to expect a user to enter a pixel coordinate value just to drop some text.
I would suggest that coordinates shouldn't be shown in the text dialog by default, and that the starting position should default to something like the middle of the visible area of the image.