Playing around with the Context-3.0 Drupal module, I found out there was a slight conflict with Zen-2.x theme that I use.
The problem arises with how Context and Zen theme handle blocks, both overriding the theme_blocks() theme hook. So, what happens is that Context's rules don't work, as Zen wins with the last hook override. So the solution, is to combine both sets of logic in a theme_blocks function in your template's "template.php". Utilizing a fix that works with Context 2.x, I came up with the following fix that works for 3.x: