org-trello seems to be inhibitting automatic updating of packages in Marmalade.
The current version of org-trello in Marmalade is 0.6.3. But this version depends on defered-0.3.2
org-trello is an available package.
Status: Available from marmalade -- [Install]
Archive: marmalade
Version: 0.6.3
Requires: request-deferred-0.1.0, deferred-0.3.2, s-1.9.0, dash-2.8.0, emacs-24 Summary: Minor mode to synchronize org-mode buffer and trello board
However, that version of deferred isn't present in Marmalade, so trying to install org-trello fails. But worse, if you're in *Packages* and try to upgrade all U, x, Emacs will generate the error:
package-compute-transaction: Need package `deferred-0.3.2', but only 0.3.1 is available
Aborting the upgrade. If you have many packages selected there's no easy way to determine which one is causing the problem. Somehow, even though org-trello wasn't an separate package in the base org that shipped with Emacs 24.3 it is considered part of the org upgrade and therefore causes upgrade all to break.
The work-around is select all for upgrade U and then deselect org-trello and then upgrade the remainder of the packages x.
The best fix for this would probably be to introduce the correct deferred package into Marmalade. An alternate solution would be to rework the org package so that org-trello is not automatically included in the upgrade.