Show block editing on hover

I am having the same issue.

If I remember correctly when I was trying Boron for Zen, before creating my own HTML5 theme for Zen, I had to add the block-editing.css file. The contents of this file are:

/**
 * @file
 * Zen's rollover edit links for blocks.
 */


div.block.with-block-editing,
section.block.with-block-editing {
  position: relative;
}

div.block.with-block-editing div.edit,
section.block.with-block-editing div.edit {
  display: none;
  position: absolute;
  right: 0; /* LTR */
  top: 0;
  z-index: 40;
  border: 1px solid #eee;
  padding: 0 2px;
  font-size: 0.75em;
  background-color: #fff;
}

div.block.with-block-editing:hover div.edit,
section.block.with-block-editing:hover div.edit {
  display: block;
}

I found the issue. The zen block editing is looking for div.block.with-block-editing div.edit

With the HTML5 entities, the block div is actually named "section". Replace the block-editing.css with this code:

/* --------------------------------------------
Block Editing on Hover 
----------------------------------------------- */

section.block.with-block-editing {
  position: relative;
}

section.block.with-block-editing div.edit {
  display: none;
  position: absolute;
  right: 0; /* LTR */
  top: 0;
  z-index: 40;
  border: 1px solid #eee;
  padding: 0 2px;
  font-size: 0.75em;
  background-color: #fff;
}

section.block.with-block-editing:hover div.edit {
  display: block;
}

I can confirm this correction helps, but...

I also hat to alter block.tpl.php from

...
  <div class="content">
    <?php print $content; ?>
  </div>

  <?php print $edit_links; ?>
...

to

...
  <div class="content">
    <?php print $edit_links; ?>
    <?php print $content; ?>
  </div>
...

I don't know if this is html5-compliant, but for me block editing is only an admin feature- so I don't mind.