Can use JSONP in Safari, but not Safari Moble!

Question

Hi,

I am trying to get an iphone webapp that uses ajax to work.

I have developed the code using the latest Windows 7 version of safari and it works fine. The same code does not work in Safari Mobile for iOS 4...

$.ajax({
    dataType: 'jsonp',
    data: "somedata=34",
    jsonp: 'jsonp_callback',
    url: 'http://www.siteName/dl.php',
    success: ParseJson
    });



enter function ParseJson(data){code won't copy into tag, but not relevant as the desktop version doesn't seem to trigger this function either}

I just don't understand what is going on... The remote script passes back an alert for me to see what is going on.

In fact, even when working, the remote script is only supposed to pass back functions.

On the desktop version, the alert pops up. On the mobile version, nothing happens.

Can anyone suggest whereI am going wrong as I though that both versions of safari worked in the same way...

Thanks,

David