jsonp解析为XML

I'm having the following problem.

I'm developing an app with Phonegap, and I have some trouble with the AJAX call on Blackberry. When I call the ajax service with datatype = 'xml', it works fine on Windows Phone, and Android but failed on Blackberry.

This is the code:

jQuery.ajax({
                url: requestedUrl,
                dataType: 'xml',
                timeout: this.timeout,
                beforeSend: _.bind(this.beforeSendCallback, this),
                success: _.bind(this.internalSuccessCallback, this),
                error: _.bind(this.internalErrorCallback, this),
                headers: {'X-Requested-With': 'XMLHttpRequest'}
            })

I read on others post, that you cannot do anXMLHttpRequest to an external domain, which is the error that Blackberry shows (but I don't understand why it works on the other two platforms.) So I try to change the dataType to 'jsonp', but a syntaxError shows up. I tried with jsonp text xml, but for some reason it does not and returns the same

Uncaught SyntaxError: Unexpected token <

Looking, the response of the WS, it gave me back a valid XML. So the question is, How can I use that XML if I'm making the call with jsonp?

EDIT:

Actually, the problem was that the "origin" header was "local:\" (my app), so BB was blocking the content of the response. The solution was to add that domain to my config.xml, like this:

<access uri="local:///" subdomains="true" />

Unlikely Android and Windows Phone, in the config.xml you have to set access to the domains with uri, not origin and the * wildcard is not allowed with XmlHttpRequest (XHR) on BlackBerry 10.