That sounds like a grid problem again, but I don't know why. A work around may be to set the grid size to .01 and see if that will let you get close enough to 90 degrees to work. Hopefully someone else may have a better suggestion. Sometimes (again on Windows anyway) the initial component placement is off the grid, in that case if you move the component with the mouse it will snap to the grid correctly. That can cause the wires to not bend correctly as they are snapping to the grid.
Peter