[zhukovia]

Решил заменой Ajax на простой запрос

paramsPOST = paramsPOST + '&print=pdf';
	var form = document.createElement("form");
	form.setAttribute("method", "post");
	form.setAttribute("action", url+"?ID="+params['ID']);
	//form.setAttribute("target", "_blank");
	var pars = paramsPOST.substr(0).split('&');
	for(var key = 0; key < pars.length; key++) {
		var el = pars[key].split('=');
                 var hiddenField = document.createElement("input");
         	hiddenField.setAttribute("name", el[0]);
        	hiddenField.setAttribute("value", el[1]);
	        form.appendChild(hiddenField);
	}
form.submit();