If a screen on Mobile Safari overflows the view-able area vertically, pressing anything on that lower 10% of the screen (while in full-screen mode) will show the iOS menu and ignore the control that was pressed. For example, if the button for making a schedule is in that bottom area, the screen will just re-position to the top and ignore the button to make the schedule.
A blank area was added to the bottom of the make schedule dialog to make it less likely for the buttons to fall in this area and makes it easier to scroll so that they are not in the 'dead zone'.
Another work-around is to use Chrome or another browser on your iPhone. These browsers do not have this issue.