POST request in Spring MVC not work after migration from 3.2 to 4.1

I send POST request

$.ajax({         
            type: "POST",  
            url: "/common/ajax/advert/",  
            data: data,
            dataType: "json",
            contentType: "application/json",
            success: function(r){}
});

to controller

@Controller
@RequestMapping(value = "/common/ajax/advert")
public class Controller {

    @RequestMapping(value="/", method=RequestMethod.POST)
    @ResponseBody
    public  Map<String,Object> adsSearch(@RequestBody Map<String,Object> data){

        Map<String,Object> result = new HashMap<String,Object>();
        List<Advert> ads =  advSrv.getAds(data);

        result.put("obj", ads);
        return result;
}

and return 404 error, but in spring 3.2 this work fine.

Controllers with RequestMethod.GET work correct in old and new version.

Please help me to fix it.

UPD.1 I tried to create a @RestController class (Spring 4.1) with RequestMethod.POST - and it did not work too.

UPD.2 In log Spring mapped this methods properly, but post request not handled (unlike get requests, they works fine).