Urgente: Problema con Insert.. Select

Hola, me tiene la paciencia llena esta cuestion, tengo esta tabla (script al
final) e intento hacer a modo de ejemplo:

INSERT INTO CM
SELECT 100 AS Consulta_ID, Num_Caja, Tipo_ID, ID,NDesde, NHasta, Nodo,
INFO, Fdesde, FHasta, LDesde, LHasta,'dd' as observa,null AS Estado_ID, NULL
AS TipoEnvio, NULL AS Cantidad, NULL AS FechaDevolucion, NULL AS
RemitoDevolucion,1 AS Sale
FROM CM

pero me da el error

Server: Msg 260, Level 16, State 1, Line 1
Disallowed implicit conversion from data type smalldatetime to data type
int, table 'SAAR.dbo.cm', column 'Ndesde'. Use the CONVERT function to run
this query.
Server: Msg 260, Level 16, State 1, Line 1
Disallowed implicit conversion from data type smalldatetime to data type
int, table 'SAAR.dbo.cm', column 'Nhasta'. Use the CONVERT function to run
this query.


A que se debe ???

Gracias



CREATE TABLE [dbo].[cm] (
[ConsultaMov_ID] [int] IDENTITY (1, 1) NOT NULL ,
[Consulta_ID] [int] NULL ,
[Num_Caja] [int] NULL ,
[Tipo_ID] [tinyint] NULL ,
[ID] [int] NULL ,
[Nodo] [varchar] (30) COLLATE SQL_Latin1_General_CP1_CI_AS NULL ,
[INFO] [varchar] (50) COLLATE SQL_Latin1_General_CP1_CI_AS NULL ,
[Fdesde] [smalldatetime] NULL ,
[Fhasta] [smalldatetime] NULL ,
[Ndesde] [numeric](18, 0) NULL ,
[Nhasta] [numeric](18, 0) NULL ,
[Ldesde] [char] (1) COLLATE SQL_Latin1_General_CP1_CI_AS NULL ,
[Lhasta] [char] (1) COLLATE SQL_Latin1_General_CP1_CI_AS NULL ,
[Observa] [text] COLLATE SQL_Latin1_General_CP1_CI_AS NULL ,
[Estado_ID] [tinyint] NULL ,
[TipoEnvio] [varchar] (10) COLLATE SQL_Latin1_General_CP1_CI_AS NULL ,
[Cantidad] [smallint] NULL ,
[Sale] [bit] NOT NULL ,
[FechaDevolucion] [smalldatetime] NULL ,
[RemitoDevolucion] [int] NULL
) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY]
GO

CREATE INDEX [IDX1] ON [dbo].[cm]([Consulta_ID]) WITH FILLFACTOR = 90 ON
[PRIMARY]
GO

CREATE INDEX [IDX2] ON [dbo].[cm]([Tipo_ID], [ID]) WITH FILLFACTOR = 90
ON [PRIMARY]
GO

insert into cm (consulta_id,sale) values (100,0)