Originally Posted by MegaBit

When the "Show All" is checked, all icons, including those you have elected to hide are shown but with an "X" through them. That gives you a chance to go back and un-hide them and re-position them.

After you get the ones you want un-hidden, you need to go back and un-check the "Show All" option to once again hide the icons you have chosen to hide.

This works the same for all default themes and any custom themes.