Bug report for 8.2.3c:

When org-agenda-sorting-strategy is set to deadline-up (or similar values),
the Global Todo list always places non-timestamped entries at the
beginning, even when org-sort-agenda-notime-is-late is true.  This is
inconsistent with the behavior when org-agenda-sorting-strategy is time-up.

I believe the problem is that the org-cmp-ts function copied a line from
the older org-cmp-time function:
(def (if org-sort-agenda-notime-is-late 9901 -1))

9901 is later than all times of day, but not later than all date/time
stamps.

I am using org-mode version 8.2.3c / 20131125 from elpa on GNU Emacs 24.3.1
(x86_64-apple-darwin13.0.0, NS apple-appkit-1265.00) of 2013-10-27

Please let me know if there are any other details I can provide.

Thanks,

Michael Crouch