Invalid HTML for shortcodes

[fergbrain]

use your plugin on a site i build and as i testing it via w3c validator, it seems to be invalide.
I must be place your [fergcorp_cdt max=1] in

tags, and its valide.
Because you use the
• tag for your countdown.

  http://wordpress.org/support/topic/make-it-valide?replies=1