Quote - I also confirm the delete-bug is very annoying. Even the menu  "Object ->Delete Object" is sometimes greyed out and therefore NOT working.

I also found that the window showing the rendered image after rendering (Pressing button ) has lost its scroll bars. So you can´t see the rendered picture

 

If the menu is greyed out it was either a figure you were deleting (use the figure menu) or something that can't be deleted like the ground or main camera etc. (At least it's been that way for me)

You don't need scroll bars on the "tear off" you can drag the image around . (Better than scroll bars in my opinion - to move down and across would be two clicks/drags on scrollbarrather than  one drag on the image)