I also have same error, but im not sure the shipping is free

Traceback (most recent call last):
  File "/usr/local/openerp/openerp-server/openerp/osv/osv.py", line 121, in wrapper
    return f(self, dbname, *args, **kwargs)
  File "/usr/local/openerp/openerp-server/openerp/osv/osv.py", line 176, in execute
    res = self.execute_cr(cr, uid, obj, method, *args, **kw)
  File "/usr/local/openerp/openerp-server/openerp/osv/osv.py", line 164, in execute_cr
    return getattr(object, method)(cr, uid, *args, **kw)
  File "/usr/local/openerp/e-commerce-addons/base_sale_multichannels/sale.py", line 290, in import_orders
    self.import_resources(cr, uid, ids, 'sale.order', context=context)
  File "/usr/local/openerp/openobject-extension/base_external_referentials/external_osv.py", line 408, in import_resources
    res = self.pool.get(resource_name)._import_resources(cr, uid, external_session, defaults, method=method, context=context)
  File "/usr/local/openerp/openobject-extension/base_external_referentials/decorator.py", line 87, in wrapper
    response = func(self, cr, uid, external_session, *args, **kwargs)
  File "/usr/local/openerp/e-commerce-addons/base_sale_multichannels/sale.py", line 507, in _import_resources
    return super(sale_order, self)._import_resources(cr, uid, external_session, defaults=defaults, method=method, context=context)
  File "/usr/local/openerp/openobject-extension/base_external_referentials/external_osv.py", line 443, in _import_resources
    res = self._record_external_resources(cr, uid, external_session, resources, defaults=defaults, mapping=mapping, mapping_id=mapping_id, context=context)
  File "/usr/local/openerp/openobject-extension/base_external_referentials/external_osv.py", line 519, in _record_external_resources
    res = self._record_one_external_resource(cr, uid, external_session, resource, defaults=defaults, mapping=mapping, mapping_id=mapping_id, context=context)
  File "/usr/local/openerp/openobject-extension/base_external_referentials/decorator.py", line 45, in wrapped
    return func(self, cr, uid, argument, *args, **kwargs)
  File "/usr/local/openerp/community/magentoerpconnect/magentoerpconnect/sale.py", line 420, in _record_one_external_resource
    res = super(sale_order, self)._record_one_external_resource(cr, uid, external_session, resource, defaults=defaults, mapping=mapping, mapping_id=mapping_id, context=context)
  File "/usr/local/openerp/openobject-extension/base_external_referentials/decorator.py", line 108, in wrapper
    return func(self, cr, uid, external_session, resource, *args, **kwargs)
  File "/usr/local/openerp/e-commerce-addons/base_sale_multichannels/sale.py", line 511, in _record_one_external_resource
    return super(sale_order, self)._record_one_external_resource(cr, uid, external_session, resource, defaults=defaults, mapping=mapping, mapping_id=mapping_id, context=context)
  File "/usr/local/openerp/openobject-extension/base_external_referentials/external_osv.py", line 539, in _record_one_external_resource
    vals = self._transform_one_resource(cr, uid, external_session, 'from_external_to_openerp', resource, mapping=mapping, mapping_id=mapping_id, defaults=defaults, context=context)
  File "/usr/local/openerp/openobject-extension/base_external_referentials/decorator.py", line 45, in wrapped
    return func(self, cr, uid, argument, *args, **kwargs)
  File "/usr/local/openerp/community/magentoerpconnect/magentoerpconnect/sale.py", line 403, in _transform_one_resource
    previous_result=previous_result, defaults=defaults, context=context)
  File "/usr/local/openerp/openobject-extension/base_external_referentials/external_osv.py", line 1106, in _transform_one_resource
    vals = self._transform_sub_mapping(cr, uid, external_session, convertion_type, resource, vals, sub_mapping_list, mapping, mapping_id, mapping_line_filter_ids=mapping_line_filter_ids, defaults=defaults, context=context)
  File "/usr/local/openerp/openobject-extension/base_external_referentials/external_osv.py", line 1249, in _transform_sub_mapping
    lines = sub_mapping_obj._transform_resources(*transform_args, **transform_kwargs)
  File "/usr/local/openerp/openobject-extension/base_external_referentials/external_osv.py", line 1003, in _transform_resources
    previous_result=result, defaults=defaults, context=context))
  File "/usr/local/openerp/e-commerce-addons/base_sale_multichannels/sale.py", line 793, in _transform_one_resource
    previous_result=previous_result, defaults=defaults, context=context)
  File "/usr/local/openerp/openobject-extension/base_external_referentials/external_osv.py", line 1082, in _transform_one_resource
    raise MappingError(e, mapping_line['name'], self._name)
MappingError: u'the mapping line : price for the object sale.order.line have an error : float division by zero'