"parseerror" in AJAX-request in IE

"parseerror" in AJAX-request in IE

Hi!
I have to make ajax-request and get JSON-data. My code succesfuly works in FireFox and Opera, but in IE error occured: "parseerror".
I have no idea what i have to do to solve this problem. Please, help me

There is my code:
   $.ajax({
      url:'blocks/city_list.php?country='+country,
      dataType: "json",
      success: function(res) {
         createNewCityList(place, res);
      },
      error: function (XMLHttpRequest, textStatus, errorThrown) {
         alert('textStatus: '+textStatus+' | errorThrown: '+errorThrown);
      }
   });