joomla/joomla-cms — pull request #247 by okonomiyaki3000 (2012-06-19 02:12:05+00:00)
Title:  use the correct json content-type header when sending json data 

Shouldn't this be fixed at a lower level?

Anyway, a fix for this:
http://joomlacode.org/gf/project/joomla/tracker/?action=TrackerItemAddAction