Survey answer gives Unicode exception on non-english surveys

I created non-english survey which has Mongolian letter in questions and answers.

When I used it in HR applicants survey it gives following error.

I am using newest 6.1 version.

Client Traceback (most recent call last):
  File "/home/sysadmin/openerp-web/branches/6.1/addons/web/common/http.py", line 180, in dispatch
    response["result"] = method(controller, self, **self.params)
  File "/home/sysadmin/openerp-web/branches/6.1/addons/web/controllers/main.py", line 1209, in load
    return self.fields_view_get(req, model, view_id, view_type, toolbar=toolbar)
  File "/home/sysadmin/openerp-web/branches/6.1/addons/web/controllers/main.py", line 1091, in fields_view_get
    fvg = Model.fields_view_get(view_id, view_type, context, toolbar, submenu)
  File "/home/sysadmin/openerp-web/branches/6.1/addons/web/common/openerplib/main.py", line 250, in proxy
    args, kw)
  File "/home/sysadmin/openerp-web/branches/6.1/addons/web/common/openerplib/main.py", line 117, in proxy
    result = self.connector.send(self.service_name, method, *args)
  File "/home/sysadmin/openerp-web/branches/6.1/addons/web/common/http.py", line 608, in send
    raise xmlrpclib.Fault(openerp.tools.exception_to_unicode(e), formatted_info)

Server Traceback (most recent call last):
  File "/home/sysadmin/openerp-web/branches/6.1/addons/web/common/http.py", line 593, in send
    return openerp.netsvc.dispatch_rpc(service_name, method, args)
  File "/home/sysadmin/openobject-server/branches/6.1/openerp/netsvc.py", line 360, in dispatch_rpc
    result = ExportService.getService(service_name).dispatch(method, params)
  File "/home/sysadmin/openobject-server/branches/6.1/openerp/service/web_services.py", line 586, in dispatch
    res = fn(db, uid, *params)
  File "/home/sysadmin/openobject-server/branches/6.1/openerp/osv/osv.py", line 167, in execute_kw
    return self.execute(db, uid, obj, method, *args, **kw or {})
  File "/home/sysadmin/openobject-server/branches/6.1/openerp/osv/osv.py", line 121, in wrapper
    return f(self, dbname, *args, **kwargs)
  File "/home/sysadmin/openobject-server/branches/6.1/openerp/osv/osv.py", line 176, in execute
    res = self.execute_cr(cr, uid, obj, method, *args, **kw)
  File "/home/sysadmin/openobject-server/branches/6.1/openerp/osv/osv.py", line 164, in execute_cr
    return getattr(object, method)(cr, uid, *args, **kw)
  File "/home/sysadmin/openobject-addons/branches/6.1/survey/wizard/survey_answer.py", line 405, in fields_view_get
    file = open(addons.get_module_resource('survey', 'report') + survey_data.title + ".pdf")
UnicodeEncodeError: 'ascii' codec can't encode characters in position 59-65: ordinal not in range(128)