I don't know if anyone else has seen this or if it's just me, but shouldn't 'zoom to drawing' do just that and zoom to show all objects in the current drawing? At the moment when I zoom to drawing it zooms out so that the A4 landscape page becomes about the size of a playing card in the centre of the screen, I'm certain X1 did not do that.
If there were stray forgotten objects outside the drawing it would zoom to encompass those objects, which is what I assumed was happening here but I can find no invisible objects outside the drawing(s) I have checked.
Bug?

Derek