Strange, did you tick show text and show title like in my post above.I can lock the taskbar and have no icons showing.
Edit - I see what you mean now when you lock the task bar it just pops into view.Not much you can do about that unless you remove the full toolbar. You could drag the full tool bar over to the left side and show all the icons. Just drag the separator bar passed and pinned icons and over to the left. If not just hide it.