I use the CodeIgniter PHP framework and one of it's features is that the GET global is destroyed.
I therefore use jQuery 1.2+ with POST for ajax/jsonp. This works in all jQuery versions, including the latest 1.2.6, for the _same_ domain. When it comes to cross-domain calls, something changed between versions 1.2.1 and 1.2.2 of jQuery. 1.2.1 works, while 1.2.2 and newer does not. Error is what you expect and the XHR connection fails to open: Access to restricted URI denied code: 1012 [Break on this error] xml.open(s.type, s.url, s.async, s.username, s.password); // earlier jQuery versions xhr.open(type, s.url, s.async); // later jQuery versions Running diffs on the files, I obviously see the changes but fail to understand the specifics that changed the behavior. If it is relevant, the submitted URL structure is as follows (pasted in an example callback function generated by jQuery at the end): http://domain.com/controller/method/var/?jsoncallback=jsonp1215426133956 Could someone with a better knowledge of the core offer some insight on what changed between 1.2.1 and 1.2.2, for remote calls, and if this can be resolved?