One line fix, so I can give it here.

templates/default/admin/editstyle.tmpl. There is a line that looks like this:

<textarea name="{$data['class']} a:hover" rows="3" cols="20"/>{$style_vars["{$data['class']} a:hober"]}</textarea>

Change that, to this:

<textarea name="{$data['class']} a:hover" rows="3" cols="20">{$style_vars["{$data['class']} a:hover"]}</textarea>