alchymyth on "Footer at top. How use clear:both to fix?"

the style of #footerback with position: fixed; does not get applied in the narrow browser window;

from Firefox' web developer add-on:

/* Line 2082 */
#footerback
{
  height: 35px;
  position: fixed;
  bottom: 0px; .........

afaik, the @media queries are applied for the wide screens; you might need to move the above style into the top section (?)

btw:
it is absolutely not recommended to edit the default theme Twenty Twelve directly, but to create a child theme for the customization; http://codex.wordpress.org/Child_Themes